Toothwear Flashcards
1
Q
Compare tooth surface loss and non-carious tooth surface loss.
A
Tooth surface loss- loss for any reason (caries/trauma/ developmental problems/toothwear)
Non carious tooth surface loss (loss due to trauma/developmental problems/toothwear)
2
Q
What is physiological tooth wear?
A
Normal wear that is associated with normal function. (20-38um per year)
3
Q
What is pathological toothwear?
A
When toothwear over the normal level expected for that patient’s age or when the toothwear is causing a mastigatory or aesthetic defect.
4
Q
List the 4 main causes of toothwear?
A
Attrition
Abrasion
Abfraction
Erosion.
5
Q
Discuss the increase in toothwear over the past 10 years.
A
It has shown an increase but the increase is not uniform.
50% of 5 year olds have toothwear of their primary incisors.
6
Q
How do we assess a patient’s toothwear.
A
- Recognise the problem is present
- Grade it’s severity
- Diagnose the likely cause or casues.
- Monitor the disease progerssion
- Active or historic
- Are preventative measures working or is active restorative treatment required?
7
Q
What are we looking for in the patient’s medical history that is relevant to toothwear?
A
- Medications
- Low pH/ causing dry mouth
- Medical conditions
- GORD
- Anaemia
- Alcoholism
- Hiatus hernia
- Pregnancy
- morning sickness
8
Q
In our assessment of a toothwear patient. What are we looking for with their TMJ.
A
- Any clicking?
- Any crepitus?
- Any restriction of movement?
9
Q
In our assessment of a toothwear patient. What are we looking for with their muscles of mastication?
A
- Hypertrophy.
10
Q
In our assessment of a toothwear patient. What are we looking for with their mouth opening? .
A
Can they open their mouth >4cm
Is there any deviation during movement?
11
Q
In our assessment of a toothwear patient. What are we looking for aesthetically?
A
Is there overclosure
Is their lip line lower?
Do they show any teeth when they smile (smile line)
12
Q
In our assessment of a toothwear patient. What are we looking for in terms of their occlusion?
A
- Assessment of:
- Freeway space
- OVD and facial height
- Has there been any dento-alveolar compensation?
- Overbite and overjet
- Are there stable contacts in cetric relation
- What are tooth contacts like in excursive moments?
13
Q
What is dento-alveolar compensation?
A
Dentoalveolar compensation is the compensation for the loss of tooth substance by dentoalveolar bone growth. The bone gets longer to prevent the incisal edge moving. This leaves no room for restorations.
14
Q
In our assessment of a toothwear patient. What are we looking for in terms of their soft tissues?
A
Dryness
Buccal keratosis or lingual scalloping (bruxism)
15
Q
How do we describe a patient’s toothwear:
A
- Location
- Localised
- Anterior/posteiror
- Generalised
- Toothwear with loss of OV (bigger freeway space)
- Toothwear without loss of OVD but space is available
- Toothwear without loss of OVD but limited space.
- Wear
- Enamel only
- Into dentine
- Severe
- Localised
16
Q
Compare Smith and Knight & BEWE for classifying toothwear.
A
Smith and night: 0-4 for each tooth
BEWE- used like a BPE grading each sextant for toothwear 0-3
17
Q
List some immediate problems presented by a patient with toothwear?
A
- Sensitivity
- TMJ
- Wear compromising pulpal health
- Nonfunctional tooth.
- Sharp edges.
18
Q
What immediate treatment can be given for a patient in pain due to wear causing sensitivity?
A
Desensitising agents
Fluorides
Bonding agents
GIC coverage of exposed dentine.
19
Q
What immediate treatment can be given for a toothwear patient in pain due to wear compromising their pulpal health.
A
Pulp extirpation.
20
Q
What immediate treatment can be given for a toothwear patient in pain due to wear causing sharp edges.
A
Smooth the sharp edges to prevent trauma.
21
Q
What immediate treatment can be given for a toothwear patient in pain due to wear causing an unrestorable/ non functional tooth.
A
Extraction.
22
Q
What immediate treatment can be given for a toothwear patient in pain due to wear affecting their TMJ.
A
Control acute symptoms.
23
Q
Discuss the initial treatment for a wear patient.
A
- Stabilise existing dentition (caries/perio/oral mucosal)
- Start a preventative regime
24
Q
What is vital to do before we begin the preventative treatment?
A
Take a baseline reading of the wear so we can monitor and see if it progresses. Using
- Wear indices- smith and knight/BEWE
- Models
- Photos.
25
What are we looking for when monitoring toothwear?
Progression- if it is actively progressing- prevention before treatment
Historic- if not causing problems- treatment
26
Describe the type of toothwear shown in this image?
The phsyiological wearing away of tooth structure as a result of tooth to tooth contact.
27
Where is attrition commonly found?
On the occlusal surface and incisal contacting surfaces
28
List some of the clinical signs of attrition?
Facets on the cusps
Flattening of cusps and incisal surfaces
Loss of cuspal height
Shortening of incisors and canine teeth.
29
What is the main cause of attrition ?
Parafunction
30
Describe the preventative treatment of attrition?
Dealing with the cause of the parafunction
Usually due to stress so treat with CBT or hypnotherapy.
Splinting teeth- so that the teeth wear down the splint rather than the teeth.
31
Compare the different types of splints that can be used to treat attrition ?
Soft splint- used diagnostically to show the patient is grinding their teeth
Hard splint- more robust/ will last longer.
Michigan splint- provides an ideal occlusion in centric so teeth are biting together in the ideal occlusion. The canine guidance causes the other teeth to disclude in lateral and protrusive excursive movements. (To reduce wear on the other teeth)
32
Describe the type of toothwear shown in this image?
Abrasion
The physical wear of tooth substance involving a foreign object or substance repeatedly contacting the tooth.
33
What is the most common type of abrasion and how does it present ?
Toothbrush abrasion-
* Labial/buccal/ cervical on canines and premolar teeth
* V shaped and rounded lesions
* Sharp margin at enamel edge where the dentine is preferentially worn away.
34
Describe the preventative treatment for abrasion?
Remove the cause- e.g. altering toothbrushing habits/ changing toothpaste/ altering other habits
35
Describe the type of toothwear shown in this image.
Erosion- the loss of tooth surface by a chemical process that does not involve bacterial action.
36
Compare earlier and later stages of erosion.
Earlier stages- Enamel surface is affected, there is loss of surface detail causing surfaces to beome flat/smooth/shiny.
Later stages- typically bilateral, concave lesions without a chalky appearance round the edges of caries (bacterial acid decalcification)
37
Why does cupping happen once dentine is exposed?
Dentine has less mineral content so it wears more quickly than enamel. This causes the cupping of the occlusal surfaces of molars and the incisal edges of the anteriors.
38
Describe the clinical appearance of erosion.
* Loss of tooth thickness- causing increased translucency of incisal edges so they appear darker /shine through)
* Base of lesion is not in contact with the opposing tooth
* Tooth dissolves away from the restoration (leaving any restorations sitting proud of the tooth)
39
Discuss preventative treatment of erosion.
* Harden the tooth surface
* High fluoride toothpaste or mouthwash
* Relief of symptoms
* Desensitising toothpaste
* If extrinsic acid
* Change diet
* Modify habits e.g. drinking with a straw/ swirling drinks around mouth.
* If instrinsic acid
* Is it medical condition- advise to see doctor
* Treat xerostomia
40
Describe the type of toothwear shown in the image.
Abfraction- Loss of hard tissue from eccentric occlusal forces causing stress at the cervical area of the tooth.
41
Describe what causes abfraction.
Forces from biting down cause the flexure and failure of enamel and dentine at the cervical margin (stress concentration)
Cyclic fatigue causes disruption of the crystalline structure resulting in the tooth cracking (parts chipping off)
42
What do we see clinically in a patient with abfraction?
V shaped tooth loss where the tooth is under tension.
Sharp rim at the amelo-cemental junction.
43
What could abfraction also be caused by?
Overbrushing as good OH and the abfraction clinical pattern go together.
44
Discuss the preventative treatment for abfraction:
Fill the abfraction cavities with a low modulus restorative matieral (RMGI or flowable composite)
45
Compare passive and active management of toothwear ?
Passive management consists of prevention and monitoring.
Active management consists of restorations covering exposed dentine and filling cupped defects.
46
What are the 5 factors that influence your treatment plan for toothwear?
* **Pattern of anterior maxillary toothwear**
* wear limited to palatal surfaces
* wear involving the palatal and incisal edges with reduced clinical crown height
* Wear limited to the labial surfaces (unusual)
* **Interocclusal space**
* If wear is rapid there won't be time for dentoalveolar compensation causing increased freeway space
* **Place required for the restorations being planned**
* **Quality and quantitiy of remaining tooth tissue (particularly enamel)**
* **Aesthetic demands of the patients.**
47
Name and describe the technique used for the reconstructive treatment of toothwear.
Dahl technique- when we add composite to incisors to prop open a patient's bite.
This leaves a posterior open bite which encourages continued eruption of the posterior teeth to fill the gap.
48
What patients are not suitable for treatment using the DAHL technique.
* Active perio disease patients
* TMJ problems.
* Orthodontics
* Implants
* Bridges
* On bisphosphonates (slow bone turnover)
49
How do we treat cervical toothbrush abrasion?
RMGIC restorations or composite restorations so the restoration is worn away rather than more tooth tissue.
50
What is the ring of confidence and how does this improve restorative success?
This the ring of enamel around the dentine helps with bonding as bonding to enamel is more successful than dentine.
51
why is lower anterior toothwear harder to fix and how do we make it more successful?
Because there is less enamel so a smaller bonding surface. By adding material to the lingual of the tooth aswell to increase the bonding area.
52
If we have anterior toothwear in the uppers and lowers, what do we fix first and why?
The lower teeth first, as they are more likely to break off.
53
The patient's toothwear has resulted in the loss of canine guidance, how do we treat this?
Add composite to the wear area to return the canine to its previous shape.
This discludes the posterior teeth preventing further damage.
54
What information to we give the patient about their Dahl treatment ?
* Your front teeth will recieve tooth-coloured fillings to cover the exposed and worn tooth surface
* This procedure will be carried out without local anaesthetic as there will no or minimal drilling to your teeth.
* We should be able to improve the appearance of your teeth
* There will be no drilling (we are only adding teeth)
* The bite will feel strange for a few days:
* Only your front teeth will touch together
* Your back teeth will gradually come back together (will take 3-6 months)
* Will be sensitivity for the first few days.
* Inital lisp due to the shape of your front teeth changing
* You may bite your lips or tounge until your bite settles.
* Any crowns/bridges/partial dentures will need replaced.
* Longevity- the restoration will not be as strong as your tooth will ever be. But it will chip over time which will need repaired.
55
Discuss the negatives of crown lengthening surgery for the treatment of excessive toothwear?
* Black triangles due to loss of the papilla by cutting the gums back.
* Sensitivity as more of the root is exposed.
* Any subsequent conventional crown preparations will be further down the root.
* Can cause unfavourable crown to root movement (increased chance of loosening if the tooth is loaded.
56
Compare the provisional and definitive treatment of toothwear?
Provisional is figuring out what is causing the wear.
The definitive treatment is treating the cause of the wear. Starting with minimum intervention treatments (e.g. prevention)
57
How do we treat patient's with generalised toothwear of the anterior and posterior?
Refer to a specialist
58
What are splints used for in the treatment of anterior+posterior generalised toothwear?
To assess the patient's tolerance of new face height. (does the muscle soreness with the new OVD get better? )
To increase the patient's OVD.
59
How can dentures be used in the treatmetn of generalised posterior + anterior toothwear?
* To increase the OVD of the patient
* To provide posterior support at the new OVD
60
Discuss overdentures as a treatment for severe toothwear
These preserve tooth substance and bone for the support of the denture when teeth are so worn down that the restoration is impossible.
They can be bulky and it is difficult to keep the teeth and gingivae healthy below the prosthesis.
61
List some modifying factors that influence attrition.
Lack of posterior teeth- more extensive & rapidly progressing wear.
Restorations (porcelain are abrasive)
Occlusion
Deep open bite causes lower incisal wear
Edge to edge bite causes localised incisal wear
Stress & anxiety clenching & grinding.
Erosion and abrasion - in combination.
62
Give some common features of physiological toothwear
Attritive wear of incisive teeth
Flat canine cusps .
63
Give some common features of bruxism.
Significant wear throughout the dentition
Repeated restoration failure
Root fractures (more concerning in virgin teeth)
Often onset in early adulthood.
Progressive.
64
What are some clinical signs of parafunctional activity that we want to look out for?
Multiple cusp fractures
Multiple cracks around restorations
Root fractures in unrestored teeth
Soft tissue changes (lip chewing/cheek chewing)
65
Compare the clinical features of a patient with intrinsic erosion e.g. bulimia to a patient with extrinsic erosion.
Intrinsic acid:
*Palatal erosion on upper teeth
*Restorations (polished/ erosion around the restoration)
*Sensitivity
Bulimic patient:
*Caries (high intake prior to vomiting)
*Altered taste
*Halitosis
*soft tissue change- Tongue damaged on lower incisors when it is forced forward while pt making themselves sick.
Extrinsic acid:
* Upper incisors (Palatal erosion & incisal edge erosion)
* Cupping on the lower molars
* Sensitivity
* Inter-proximal caries and buccal white spot/brown spot lesions.
66
List some examples of combination wear problems.
Eating disorder (Erosion- intrinsic and extrinsic. Abrasion. Attrition.
Alcoholic (Erosion- intrinsic and extrinsic. Abrasion. Attrition)
Bruxism with poor diet- extrinsic erosion & attrition.
GORD with poor diet & bruxism- intrinsic & extrinsic erosion/ attrition.
67
Why are dentures often used in toothwear treatment?
Because the lack of posterior support is a modifying factor.
68
Why do we avoid complete dentures in toothwear cases?
Because the bruxism will not stop- causing fractured dentures/ridge resorption/pain and ulceration
69
What is an overdenture?
A removable prosthesis that rests on one or more remaining natural teeth, the roots of natural teeth
70
Give some advantages of overdentures?
Retention
Support- Retention of teeth means the denture uses tooth support
Provides stability- Wearing down the teeth to fit the overdenture improves the occlusal plane.
Retaining the teeth keeps the PDL- so you have better proprioception.
Can be used with precision attachments.
For MRONJ or Radiotherapy patients (avoids extraction)
71
Give some disadvantages of overdentures?
Need good oral health
Increases caries and periodontal problems.
Denture fracture risk- the leftover teeth take up space so there is less acrylic which makes the denture more prone to fracturing.
Could get discomfort of infection of the roots.
72
How do we care for overdentures?
Good oral hygiene
Denture hygiene
Applying fluoride toothpaste to the roots.
Regular examinations and radiographs.
73
What are transitional dentures ?
These are temporary dentures used when we want to increase a patients OVD. This helps us see if the patient can tolerate the new OVD. The patient wears it for a few months.
The new OVD is the height the teeth would be at if there wasn't toothwear.
74
Describe some metal based dentures we can use for patients with bruxism?
Metal palate with an acrylic post dam-
Cobalt chrome backing- Where cobalt chrome is extended onto the occlusal surface of the teeth.
Overlay denture- This overlays teeth to protect the remaining teeth.
75
What is the best way to treat bruxist patients with saddles?
Conventional bridge (the metal ceramic bridge pontic would be much stronger than a denture tooth)
If we are using an adhesive bridge the tooth needs to be out of the way of any lateral or protrusive movements (risk of debonding)
76
What do we need to plan a toothwear case?
Impressions & facebow measurements
Clinical photographs and radiographs
Mounted articulated casts on a semi-adjustable articulator (with surveying)
Interocclusal record (at original OVD and planned OVD)
Diagnostic wax up- what the teeth would look like at the new OVD.
77
What makes an indirect restoration possible for a toothwear case?
if 50% of the tooth structure is above the gingival margin.
78
Discuss the different materials we can use to restore an indirect restoration for a toothwear case?
Porcelain - aesthetic but more brittle (patient will grind through it)
Metal (more ductile so we want to use it on the biting surfaces)
So best idea would be to restore with metal on occlusal working cusps.
We want to modify the restorations to use them in toothwear (e.g. porcelain mesiobuccal cusp & metal on the rest of the biting surfaces.)
79
What makes tooth preparation for an indirect restoration of a toothwear case difficult?
Lack of occluso-gingival height (a crown prep would have very little resistance)
Lack of occlusal space
Severely compromised teeth
80
What are grooves and inlays?
How do these help retention?
These are indents into the prep that are paralleled with the path of removal.
Insertion into these reduces the radius of rotation .
81
How can we retain the ferrule ?
Use a metal post on the top instead of preparing the dentine
82
Discuss the advantages and disadvantages of a parallel crown prep?
Adv- More coronal dentine left for retention
Disadv-Less aesthetic (paralell prep does not leave enough space to add the layer of aesthetic porcelain on top of the opaque porcelain to mask the metal)
83
How does electrosurgery help with retention?
This takes away part of the gum to allow an impression of the subgingival restoration to use as a ferrule.
84
How do we prepare a MCC in toothwear cases ?
We hardly prepare the palatal aspect to save tooth tissue & use a metal surface (less tooth prep for a metal margin)
85
What is surgical crown lengthening and how does it improve the retention of an indirect restoration in a toothwear case?
Removal of bone around the tooth & suturing of excess gum more apically. The gingival margin should heal at a lower height which gives us more clinical crown height.
You need to use a temporary crown for 3 months (until the gingival height stabilises)
86
What do we need to consider when planning the demolition of an existing restoration?
The risks and benefits of demolishing a restoration on the patient's health and appearance.
How long is the restoration expected to last and to highlight the cycle of replacement.
Dental health risk assessment- should we be replacing the tooth or extracting it?
87
What are the basic principles of dental demolition?
Operator safety (sharps risk with indirect restorations e.g. post)
Patient safety (eye and airway protection)
88
what bur do we use to cut a porcelain indirect restoration?
coarse diamond
89
What bur do we use to cut through a metal indirect restoration?
Gold cutting bur
90
When would we use the sliding hammer for removal of an indirect restoration?
Last resort- It is not comfortable for the pateint
91
Explain the process of removing an indirect restoration?
1. Cut the whole way up the buccal surface then use an enamel chisel to split things apart.
2. May need to cut onto the occlusal or palatal surface
3. May need to section horizontally.
92
What do we need to consider when planning to remove a post?
* The risk of fracture & ease of removal (dependent on length/taper/remaining dentine)
* That the tooth is already compromised.
93
Compare the different methods of post removal ?
Post puller or fine extraction foreceps
But these are difficult in mobile teeth as if you rotate too hard you can extract the tooth.
Masseran kit- this goes counterclockwise to unscrew the post (some posts go in clockwise)
