Restorative Flashcards
What are the causes of tooth surface loss?
Caries
Trauma
Developmental problems
Toothwear
What is the definition of tooth wear?
A normal physiological process that increases with increasing age
What is the definition of physiological tooth wear?
Normal wear associated with function
What is the estimated normal toothwear per year?
20-38 um
What is the definition of pathological tooth wear?
Occurs if the remaining tooth structure or pulpal health is compromised
The rate of tooth wear is excessive to the patients age
The patient may experience a masticatory or aesthetic deficit
What are the causes of tooth wear?
Attrition
Abrasion
Erosion
Abfraction
What is the definition of attrition?
The physiological wearing away of tooth structure as a result of tooth to tooth contact
Where are attritive lesions found?
On the occlusal and incisal contacting surfaces
What is the early appearance of attritive toothwear?
Polished facet on a cusp or slight flattening of an incisal edge
What does the progression of attritive toothwear lead to?
Reduction in cusp height
Flattening of occlusal inclined planes
Shortening of the clinical crown of the incisor and canine teeth
What habit is attrition associated with?
Bruxism
What is the definition of abrasion?
Then physical wear of tooth substance through abnormal mechanical process independent of occlusion.
Involves a foreign object or substance repeatedly contacting the tooth
What are the features of abrasion?
Site and pattern associated to the abrasive element
Labial/buccal, cervical on canine and premolar teeth
V shaped or rounded lesions
What is a common cause of abrasion?
Toothbrushing
What is the definition of erosion?
The loss of tooth surface by a chemical process that does not involve bacterial action
What are the features of early stage erosion?
Enamel surface affected
Loss of surface detail
Surfaces become flat and smooth
Bilateral, concave lesions without chalky appearance of bacterial acid decalcification
What are the features of later stage erosion?
Dentine becomes exposed
Preferential wear of dentine leads to ‘cupping’ of the molar surface and incisal edges of molars
What is the positioning and severity of erosive wear dependent on?
Source, frequency, and type of exposure to acid
What are the features of erosion?
Increased translucency of incisal edges (can appear dark)
Base of lesion not in contact with opposing teeth
Amalgam and composite restorations stand proud of the tooth
No tooth staining
What is the definition of abfraction?
The loss of hard tissue from eccentric occlusal forces leading to compressive and tensile stresses at the cervical fulcrum areas of the tooth
What are the two theories of abfraction?
- Abfraction is the basic cause of all non-carious cervical lesions
- Multifactorial aetiology; a combination of occlusal stress, abrasion and erosion
What are the causes of abfraction?
Caused by biomechanical loading forces that result in flexure and failure of enamel and dentine at a location away from loading
What is the impact of mechanical loading on enamel crystals (abfraction)?
Disruption of the ordered crystalline structure of the enamel and dentine by cyclic fatigue
What are the causes of cervical wear?
Multifactorial; tooth brushing
Where are cervical wear lesions usually?
Premolar and molars on the buccal surface (rarely lingually)
What is the most common type of tooth wear in older patients?
Physiological
What percentage of adults have wear in their anterior teeth (2009 Adult Dental Health Survey)?
77%
Which gender is toothwear more prevalent in? (2009 Adult Dental Health Survey)
Males: 70%
Females: 60%
What percentage of adults have severe tooth wear (2009 Adult Dental Health Survey)?
2%
What percentage of 5 year olds have tooth wear on their primary incisors? (2013 Children’s Dental Health Survey)
> 50%
How should tooth wear be assessed?
Recognise the problem
Grade its severity
Diagnose the likely cause
Monitor the progression; active or historic, are preventive measures working?
What are the features of C/O to be included in a tooth wear patient?
Aesthetic impairment
Functional difficulties (mastication, biting tongue or lips)
Pain
What are the features of C/O to be included in a tooth wear patient?
Aesthetic impairment
Functional difficulties (mastication, biting tongue or lips)
Pain
What are the features of a MH to be considered in a toothwear patient?
Medications with low pH
Medications that cause dry mouth
Eating disorders
Alcoholism
Heartburn
GORD
Hiatus hernia
Rumination
Pregnancy
What are the features of a DH that should be considered for a toothwear patient?
Dental attendance: poor attender/phobic not good candidate for complex tx plans
Precious experience/tx
Oral hygiene habits: toothbrushing
What are the features of a SH that should be considered for a toothwear patient?
Lifestyle stresses (bruxism)
Occupational details
Alcohol consumption
Dietary analysis
Habits
Sports
What are the features of an E/O exam for a toothwear patient?
TMJ; restriction of movement, clicking, crepitus
Hypertrophy of musculature
Restriction of mouth opening (<4cm)
Deviation during movement
Parotid hypertrophy
Overclosure
Lip line
Smile line
What features of occlusion should be checked in a toothwear patient?
Freeway space
Record OVD and resting face height
Is there dento-alveolar compensation
Record overbite and overset
Are there stable contacts in centric relation
What the tooth contacts are like in excursive movements
What features of an Intraoral exam should be done for toothwear patients?
Soft tissues- dryness, buccal keratosis, lingual scalloping
Oral hygiene
Perio assessment: BPE, pocket charting
Dental charting
What features of toothwear should you note in a wear examination?
Location: anterior/posterior/generalised
Severity: enamel only/into dentine/severe
What is a 0 on the Smith and Knight Toothwear Index?
No loss of enamel surface characteristics
What is a 1 on the Smith and Knight Toothwear Index?
Loss of surface enamel characteristics
What is a 2 on the Smith and Knight Toothwear Index?
Buccal, lingual and occlusal loss of enamel exposing dentine for less than one third of its surface
Incisal loss of enamel
Minimal dentine exposure
What is a 3 on the Smith and Knight Toothwear Index?
Buccal, lingual and occlusal loss of enamel, exposing dentine for more than one third of the surface
Incisal loss of enabler
Substantial dentine exposure
What is a 4 on the Smith and Knight Toothwear Index?
Buccal, lingual and occlusal complete loss of enamel, pulpal exposure or exposure of secondary dentine
Incisal pulp exposure or exposure of secondary dentine
What is a 0 on the Basic Erosive Wear Examination? (BEWE)
No erosive wear
What is a 0 on the Basic Erosive Wear Examination?
No erosive wear
What is a 1 on the Basic Erosive Wear Examination? (BEWE)
Initial loss of surface texture
What is a 2 on the Basic Erosive Wear Examination? (BEWE)
Distinct defect: hard tissue loss <50% of surface
What is a 3 on the Basic Erosive Wear Examination? (BEWE)
Hard tissue loss >50% of the surface area
How is the Basic Erosive Wear Examination (BEWE) risk level calculated?
Cumulative score of all sextants
Which arch is a Michigan splint for?
Upper arch
What is a Basic Erosive Wear Examination (BEWE) risk of none?
Cumulative score of <=2
What is a Basic Erosive Wear Examination (BEWE) risk of low?
Cumulative score 3-8
What is a Basic Erosive Wear Examination (BEWE) risk of medium?
Cumulative score 9-13
What is a Basic Erosive Wear Examination (BEWE) risk of high?
Cumulative score >14
What special tests can be carried out for toothwear patients?
Sensibility testing
Radiographs
Articulated study models
Intra-oral photographs
Salivary analysis
Diagnostic wax up
Dietary analysis
What are the features of generalised toothwear?
Wear with loss of OVD
Wear without loss of OVD, but with space available
Wear without loss of OVD, but with limited space
What are the immediate treatment options for toothwear patients with sensitivity?
Desensitising agents: fluorides, bonding agents, GIC coverage of exposed dentine
What are the immediate treatment options for toothwear patients with pain?
Pulp extirpation (if compromised pulpal health)
Smooth sharp edges (prevent trauma to cheeks and tongue)
Extraction (unrestorable)
TMJ pain
What are the initial treatment options for a toothwear patient?
Stabilise existing dentition
Deal with caries
Deal with Perio condition
Oro-mucosal
Preventive regime
What are the methods of baseline wear recording?
Wear indices: Smith and Knight, BEWE
Models
Photos
What can be done preventatively for abrasion patients?
Remove the foreign object or substance
Change toothpaste (less abrasive)
Alter tooth brushing habits
Change habits; nail biting, wire stripping, piercing/pen biting
What can be done preventatively for patient with cervical tooth brush abrasion?
RMGIC, GIC, composite or flowable restorations
RMGIC first choice (best survival), but aesthetically composite
What can be done preventatively for patient with cervical tooth brush abrasion?
RMGIC, GIC or composite restorations
What can be done preventively for patients with attrition?
Treat parafunction: cognitive behavioural therapy, hypnosis
Splinting
What are the advantages/disadvantages of hard/soft/michigan splints for attrition patients?
Hard splints: more robust, last longer
Soft splints: diagnostic device (shows wear facets as wears rapidly)
Michigan splint: hard splint; provides an ideal occlusion with even centric stops, has a canine rise which provides disclusion in eccentric mandibular movements
What can be done preventatively for erosion patients?
Fluorides
Desensitising agents (symptomatic relief)
Dietary management
Habit changes
Treat medical causes
What are the habit changes that can be implemented for erosion patients?
Stop swirling drinks in mouth
Drink with straws
Stop rumination (regurgitation of food)
Healthy eating - increased acidic fruit
Vegan diet - increased acidic dressings
Avoid sports drinks/gels
What can be done preventatively for abfraction patients?
Consider occlusal equilibrium
Fill cavities with low modulus restorative materials; RMGIC/flowable
What are the features of passive management?
Prevention and monitoring (around 6 months)
What are the features of active management of toothwear?
Simple restorative intervention
What are the goals of the of the active management of toothwear?
Preservation of remaining tooth structure
Pragmatic improvement in aesthetics
Functioning occlusion
Stability
What are the considerations to be made in the treatment planning for the active management of maxillary anterior toothwear?
The pattern of anterior maxillary tooth wear
Interocclusal space
Space required for the restorations being planned
Quality and quantity of remaining tooth tissue
The aesthetics demands of the patient
How is maxillary anterior toothwear categorised?
Toothwear limited to the palatal surfaces only
Toothwear involving the palatal and incisal edges with reduced clinical crown height
Toothwear limited to labial surfaces
In Maxillary Anterior tooth wear what may cause cases where there is adequate inter incisal space?
Teeth that wear rapidly and there is no time for alveolar compensation
Where there is an anterior open bite
Where there is an increased overjet
What would be the initial treatment aim for patients with maxillary anterior tooth wear?
Create space for traditional restorations
What are the treatment options for making space anteriorly?
Increase OVD
Occlusal reorganisation from ICP to RCP
Surgical crown lengthening
Elective RCT and post crowns
Conventional orthodontics
How can you increase the OVD in patients with anterior tooth loss?
Multiple posterior extra coronal restorations
What are the disadvantages of increasing the OVD in patients with anterior tooth surface loss?
Complex
Destructive
Expensive
What are the disadvantages of occlusal reorganisation from ICP to RCP in patients with anterior tooth surface loss?
Complicated
Destructive
Specialised treatment
What are the disadvantages of surgical crown lengthening in patients with anterior tooth surface loss?
Doesn’t really create more space
What are the disadvantages of elective RCT and post crowns in patients with anterior tooth surface loss?
Very destructive
What are the disadvantages of conventional orthodontics in patients with anterior tooth surface loss?
Lengthy treatment
What is surgical crown lengthening?
Exposure of more of the crown for retention of final restoration
Repositioning of the gingivae apically with removal of the bone
May cause sensitivity and need occlusal reduction
What is the DAHL technique?
Method of gaining space in cases of localised toothwear
Originally a removable CoCr anterior bite plane (now composite)
Covering palatal surfaces and allowing occlusion on raised cingulum
Results in posterior disclusion and increase in OVD of 2-3mm
Occlusal contacts only on incisor/canine teeth
What are the effects of the DAHl technique?
3-6months later
Gained space between incisor teeth
Interiors intrude
Posteriors erupt
What are the advantages of doing the DAHL technique with composite?
Better aesthetics
Better compliance
Easier to adjust
Immediate, definitive treatment
What are the features of the DAHL techniques success?
Faster effect in younger patients
Variable degree of effect
If no movement in 6 months; will not work
Success rate >90%
What patients are not suitable for the DAHL technique?
Active periodontal disease
TMJ problems
Post orthodontics
Bisphosphonates
Dental implants
Conventional bridges
What is the ideal patient for the DAHL technique?
Localised anterior tooth wear
What is the ideal patient for the DAHL technique?
Localised anterior tooth wear
What type of tooth loss should a splint not be provided for?
Erosion
What is the definition of a bridge?
A fixed prosthesis that replaces lost or missing teeth
What are the two main objectives of patient assessment for bridgework?
Determine the patient’s requirements and expectations
Determine the patients suitability for bridgework
Why are periodical radiographs essential in bridgework?
Assess:
Alveolar bone levels
Width and completeness of periodontal membrane space
Root form and length
Extent and adequacy of coronal restorations
Pre-existing endodontic treatment
What are three special investigations for bridgework?
Sensitivity testing
Periodical radiographs
Study casts
What are the three objectives of a bridgework treatment plan?
Control and prevention of further disease
Satisfy patient expectations and requirements
Take account of long term maintenance
What are the two main types of bridge?
Conventional
Adhesive
Which type of bridge is more conservative?
Adhesive
What are the three design types of bridges?
Fixed-fixed
Direct (rigid) cantilever
Fixed-movable
Describe fixed-fixed design:
Retainers at each end of the edentulous span connected rigidly by the pontic
Describe direct (rigid) cantilever design:
Pontic retained by a single retainer at one end of the span only
Describe fixed-movable design:
Retainers at each end of the span joined by a moveable connector
What should happen in the first appointment for a bridgework patient?
History and clinical examination
Upper and lower alginate impressions
Facebow transfer
Interocclusal record (if needed)
Periapiclas of abutment teeth
Complete laboratory prescription
What is the laboratory prescription for the first bridgework appointment?
Please provide duplicate study casts in dental stone mounted on the articulator in ICP
What should happen in the second appointment for bridgework?
Treatment options explained to patient
Consent obtained
Special tests if needed
May request a vacuum formed splint to provide an immediate provisional bridge following abutment preparation
What should you do in the third bridgework appointment?
Take a pre-preparation putty index (for protemp)
Provide anaesthesia
Prepar bridge
Take post-preparation impression
Record the occlusion
Cement provisional or vacuum formed splint
What should the lab card for bridgework post tooth preparation say?
Pour impressions
Explain the bridge design and material
What should you do in the fourth bridgework appointment?
Try in and fit
Check bridge seats fully and doesn’t rock
Check marginal integrity
Check and adjust occlusal contacts
Ask patient to confirm approval of aesthetics and comfort prior to cementation
Cement (usually RMGIC) and removed excess
Provide cleaning instructions and post op instructions to patient
What features should you look at in a bridgework review?
Marginal adaption
Occlusal function
Tissue response/effectiveness of oral hygiene measures
What is the definition of a Pontic?
Artificial replacement of the missing tooth or teeth
May be made of porcelain, acrylic or metal
What is the definition of a Retainer?
The restoration to which the Pontic is involved
Intra or extra coronal
What is the definition of a Connector?
The device that fixes the Pontic to the retained
May be a soldered joint, cast structure, dovetail or stress breaker
What is the definition of an Abutment?
Tooth or teeth that supports and holds the retainers.
What is the definition of a Saddle? (bridgework)
The area between abutment teeth
What is the occlusal reduction for porcelain and metal crowns?
2.5mm
What is the occlusal reduction for a metal crown?
1.5mm
What is the axial reduction for a metallic crown?
1.5mm buccal shoulder
5-7 degree taper
What is the occlusal reduction for a ceramic crown?
2.5mm
What is the axial reduction for a ceramic crown?
1.5-2mm buccal shoulder or chamfer
What are the four features of a metal ceramic crown prep?
Lingual chamfer
Buccal shoulder
Functional cusp bevel
Occlusal reduction
What are the features for a ceramic crown preparation?
Occlusal reduction
Chamfer margins
Axial reduction
Round line angles
What are the 7 stages of crown preparation?
Occlusal reduction
Separation
Buccal reduction
Palatal or lingual reduction
Chamfer finish
Occlusion check
Polish
What method can be used to get extra retention in a crown prep?
Grooves or slots prepared into the tooth
What is the effect of longer crown prep walls?
Longer walls interfere with tipping displacement
How can the retention of a crown be improved?
By limiting the number of paths of insertion
What are the options of finish lines for crown preparation margins?
Knife edge
Bevel
Bevelled shoulder
Chamfer
Shoulder
What are the important factors of crown prep to maintain periodontal health?
Margins: smooth and exposed to cleansing action, must be placed where dentist can finish them and patient can clean them
What is the preparation for a metal crown?
0.5mm axial
0.5mm non functional cusp
0.5mm chamfer
1.5mm occlusal functional cusp
What is the preparation for porcelain crowns?
1mm axial
1mm non functional cusp
1mm shoulder
1.5mm occlusal functional cusp
What is the preparation for a metal ceramic crown?
1.3mm axial
1.3mm non functional cusp
1.8mm functional cusp
0.5mm chamfer (metal)
1.3mm shoulder (porcelain)
What is the preparation for a ceramic crown?
1.5mm axial
1.5mm non functional cusp
1-1.5mm chamfer
2mm functional cusp
What aspects of consent should be discussed to a crown patient?
Invasiveness of procedure
Possible complications
Costs involved
Likely longevity and success rate
Time involved
Alternative options
What are the clinical stages of an indirect restoration?
Preparation
Temporisation
Impressions and occlusal records
Cementation
What are the functions of provisional restorations?
Restore aesthetics and function
Prevent sensitivity and micro leakage of bacteria
Coronal seal of endo treatment
Preserve or improve function
Prevent drifting or tilting of prepared teeth
Maintain gingival health and contour
Isolation for RCT
Matrix for core build up
What are the options for preformed provisional crowns?
Polycarbonate (silica)
Clear plastic
Metal
What is the treatment option for anterior teeth with intact marginal ridges?
Composite restoration
What is the treatment option for anterior teeth with intact marginal ridges and a discoloured crown?
Bleaching or Veneer
What is the treatment option for anterior teeth with marginal ridges that are destroyed?
Core build-up with crown
Post crown
What is the aim of a post/core?
Gains intraradicular support for a definitive restoration
What does a core do?
Provides retention for a crown
What does a post do?
The post retains the core
When is a post unnecessary in incisors and canines?
If there is sufficient coronal dentine
Why should a post be avoided in mandibular incisors?
Thin/tapering narrow mesiodistal roots
Where should a post be placed in a premolar?
In the widest root cana
They have small pulp chambers and tapering roots
What type of canals should you avoid placing a post in?
Curved
How much root filling should be below a post?
4-5mm apically
What is the specification for the width of a post?
No more than 1/3 root width at narrowest point
1mm circumferential dentine
What is the minimum amount of post that should be in the root?
At least half
What is the minimum ratio of post length: crown length
1:1
What are the ideal dimensions of a ferrule?
At least 1.5mm height and width of remaining coronal dentine
What is a ferrule?
Dentine collar
What does a ferrule do?
Prevents tooth fracture
What are the three ideal features of a post?
Parallel sided
Non-threaded
Cement-retained
Why should a post be non-threaded?
Smooth surface incorporates less stress to remaining tooth than threaded
Why should a post be parallel sided?
Avoids wedging
More retentive than tapered
Why should a post be cement retained?
Less retentive than threaded posts but cement acts as a buffer between masticatory forces and post/tooth
Which metals can be used as a post?
Cast gold
Stainless steel
Brass
Titanium
What are the benefits/downsides of metals as posts?
Poor aesthetics
Root fracture
Corrosion
Nickel sensitivity
Radiopaque on radiograph
Which ceramics can be used as a post?
Alumina
Zirconia
What are the benefits/downsides of ceramics as a post?
High flexural strength
High fracture toughness
Favourable aesthetics
Difficult retrievability
Root fracture
What fibres can be used as a post?
Glass
Quartz
Carbon
What are the benefits/downsides of fibres as a post?
Flexible
Similar to dentine
Aesthetic
Retrievable
Bond to dentine (DBA)
Radiolucent on radiograph
What are the options for a core material?
Composite
Amalgam
Glass Ionomer
What are the benefits/downsides of composite as a core material?
Good aesthetics
Bonds to tooth
Technique sensitive
Moisture control needed
Fibre posts used
What are the benefits/downsides of amalgam as a core material?
Poor aesthetics
Needs retention
24hr set
What are the benefits/downsides of glass ionomer as a core material?
Absorbs water and swells
How are posts removed?
Ultrasonic
Eggler device
Sliding hammer
Trephan: Masseran
Moskito forceps (screw-retained)
Anthrogyr (safe relax)
What are the reasons for post failure?
60% restorative problems
32% periodontal problems
8% endo problems
What are intrinsic causes of tooth discolouration?
Tetracylines
Pulp necrosis
Internal bleeding
Amalgam
Fluorosis
What are the extrinsic causes of tooth discolouration?
Smoking
Coffee and tannins
CHX
Iron
Enamel defects
What are the stages of crowns?
Preparation
Temporisation
Impressions and Occlusal Records
Cementation
What is class 2 div 1 incisor relationship?
The upper incisors are proclined (increased overjet)
The lower incisors occlude posterior to the upper incisors
What is class 1 incisor relationship?
The lower incisors occlude or lie immediately below the cingulum plateau of the upper incisors
What are the aims of occlusal reduction?
Retain some morphology but reduce cusps and marginal ridges
Which burs should be used of occlusal reduction?
Diamond tapered fissure bur
Rugby ball bur
What bur should be used for separation in crown prep?
Long tapered diamond bur
What are the two planes used in buccal reduction?
1- using a diamond tapered shoulder bur
2- Same bur but follows the incline of the cusp
What is the function of a core?
Gains intraradicular support for a coronal restoration
What are the two types of post?
Preformed
Custom made
What materials can be used as posts?
Cast metal (type IV gold/Au)
Steel
Zirconia
Carbon/glass fibre
What are the features associated with length of a post?
More than or equal to crow height- 2/3 root length
4-5mm root filling left apically
Reaches alveolar crest
What are the features associated with width of post?
No more than 1/3 of root width at narrowest point
1mm remaining circumferential dentine
What are the features associated with width of post?
No more than 1/3 of root width at narrowest point
1mm remaining circumferential dentine
What is the effect of occlusal trauma on a healthy periodontium?
Area of intermittent pressure and tension
Widening of pdl
Hypermobility
In absence of plaque, gingival margin remains intact
What is the response of a healthy periodontium to occlusal trauma?
Pdl width increases until forces are adequately dissipated (increase in mobility)
Pdl width then stabilises and returns to normal if demand/forces reduce
If forces cannot be adequately dissipated, pdl continues to widen until tooth is lost (pathological failure of adaption)
What is the effect of occlusal trauma on healthy but reduced periodontium?
Previous LoA and bone resorption
Tooth effectively on fulcrum
What is the effect of occlusal trauma on a diseased periodontium?
Zone of co-destruction (physiological and pathological)
Occlusal forces cause PDL widening at base of pocket and may cause clinical attachment loss (pathological) or excessive bone loss (combination of pressure and pathology)
What are the causes of mobility?
PDL width
PDL height
Inflammation
Shape/number/length of roots
When is mobility unacceptable?
Progressively increasing
Symptomatic
Associated with deep pockets
What is the treatment of mobility?
Treat perio/inflammation
Correct occlusal relations (selective grinding)
Splinting
Why is splinting a treatment of last resort for mobility patients?
Causes OH difficulties
Does not influence rate of disease progression
What are the reasons for teeth migration?
Unfavourable occlusal forces
Unfavourable soft tissue profiles
What is the treatment of migration?
Accept and stabilise
Correct occlusal relations
Orthodontics
Treat perio
When can anterior wear be restored definitively with confidence?
Relatively minimal and limited to palatal surfaces of teeth
What are the conta indications in regard to restoring anterior wear?
Short roots
Reduced periodontal support due to Perio
What feature of teeth affected by tooth wear has a positive influence on retention?
Enamel ring of confidence
Which arch should be modified in order to increase the OVD?
Upper
What is the treatment option of localised posterior tooth wear?
Filled directly with composite (no change in occlusion)
How can composite build up focus on reestablishing canine guidance?
Adding composite resin to the palatal of upper canines to increase the canine rise and disclude the posteriors during lateral and protrusion excursions
What are the stages of carrying out a composite buildup using a clear vacuum-formed matrix/stent?
Alginate impression
Diagnostic wax-up
Impression poured into stone
Vacuum formed clear matrix formed on this
Cut to size and used as mould for build up
What factors are associated with the success of composite build up with a clear vacuum formed stent?
Good patient satisfaction
Posterior occlusion normally re-achieved
Seldom TMJ problems
No detrimental effect on pulpal health
No worsening of periodontal condition
What factors affect the longevity of compite build ups carried out using a vacuum-formed stent?
Viable medium term option
Requires repair and maintainance (must inform pts)
Maxillary restorations last better than mandibular (increased bonding area)
What information should you give patients about composite buildups?
Front teeth will receive tooth coloured fillings to cover the exposed and worn tooth surface (prev further toothwear)
No local anaesthetic used as there is no/minimal drilling to teeth
Possibility of improvement in tooth appearance
Bite may feel strange for a few days- difficulty chewing, only front teeth touch initially, then back teeth will touch again in a few months
Bite should feel normal after a week or so
May cause tenderness and/or lisping
Crowns/bridges/partial dentures will likely need replaces
What information should you give patients about the longevity of composite build-ups?
Good longevity but chance of them debonding and falling off (can be replaced)
Requires maintainance; occlusal polishing, repair of chipping
What three categories can generalised toothwear be divided into?
Excessive wear with loss of OVD
Excessive wear without loss of OVD but with available space
Excessive wear without loss of OVD and with no space available
What can be used to assess a toothwear patients tolerance of an increased OVD?
Splint
How should the OVD increase be split over maxillary and mandibular arches?
Half and half
What type of generalised tooth wear should a specialist opinion be of benefit when treatment planning?
Excessive toothwear without loss of OVD with no space available
What are the treatment options for excessive toothwear without loss of OVD with no space available?
Attempt to increase OVD by use of splints +/- dentures if lack of posterior support
Crown lengthening surgery
Elective endodontic
Orthodontics
Over dentures
What are the down sides of crown lengthening surgery?
May result in black triangles
Unfavourable crown to root ration
Post op sense
Crown prep will be further down the root
What are the downsides of overdentures in a toothwear patient?
Bulky
Difficulty keeping teeth and gingiva healthy
What is the benefit of overdentures in tooth wear patients?
Preserve tooth substance and bone
What are the features of risk management in toothwear?
Should be noted; whether stable or progressing
Advice should be given and recorded in patient notes aswell as patient compliance
Topical surface treatments should be recorded
What are the features of consent for toothwear patients?
Patient must understand the proposed treatment inc passive prevention
Patient must understand their part in the treatment and how their co-operation is integral to a favourable outcome
The patient must understand the consequences of not following the advice given
What are the features of consent for toothwear patients?
Patient must understand the proposed treatment inc passive prevention
Patient must understand their part in the treatment and how their co-operation is integral to a favourable outcome
The patient must understand the consequences of not following the advice given
What are the indications for veneers?
Aesthetics
Peg-shaped laterals
Reduce or close diastemas
Hypoplasia or hypomineralisation
Erosion or abrasion
Fluorosis
Discolouration
How long should you splint an avulsion/extrusion?
2 weeks
What are the principles of cavity preparation?
Identify and remove carious enamel
Remove enamel to identify maximal extent of the lesion at the ADJ and smooth enamel margins
Progressively remove peripheral caries in dentine, from the ADJ first, then circumferentially deeper
Remove caries over pulp
Outline form modification; enamel finishing, occlusion, requirements for restorative material
Internal design modification; internal line and point angles, requirements for restorative material
What is vitrebond?
Glass ionomer liner/base
What is vitremer used for?
Glass ionomer for Core build up/ restorative
What is vitreplex?
CaOH for endodontics
How does bleaching work?
Causes oxidation which breaks down molecules into smaller ones
What is the main ingredient in bleach?
Carbamide peroxide
What does carbamide peroxide break down into?
H2O2 and urea
Urea stabilises H2O2 and increases pH
What is the role of carbamol in bleaching?
Thickening agent
What is the role of fluoride in bleaching?
Desensitising agent
What is the regulation for OTC whitening?
Less than 0.1%
What is the regulation for dental whitening?
0.1-6%
What are examples of indirect restorations?
Veneers
Inlays
Onlays
Crowns
Bridges
What are the principles of crown preparation?
Preserve tooth structure
Retention and resistance
Structural durability
Marginal integrity
Preservation of the periodontium
Aesthetic considerations
Why must you preserve sound tooth in crown preparation?
To avoid weakening the tooth structure and damage to the pulp
What can the under preparation of a crown preparation lead to?
Poor aesthetics
Overbuilt crown with perio and occlusal problems
Restorations with insufficient thickness
What can the over preparation of crowns lead to?
Pulp and tooth structure compromised
What is the principles of retention in crown preparation?
To prevent removal of the restoration along the path of insertion or the long axis of the tooth prep
What is the principles of resistance in crown prep?
To prevent the dislodgement of the restoration by forces directed in apical or oblique direction and prevents any movement of the retention under occlusal forces
What is the taper of crown prep?
6-10 degrees
What features of crown prep allow retention and resistance?
Taper
Length of walls
Limited path of insertion
Extra means of retention
What do longer walls allow in crown preparation?
Decreased tipping
What is the path of insertion?
Imaginary line along which the restoration will be placed and removed
What are the extra means of retention?
Grooves
Slots
What is structural durability?
The restoration must contain a bulk of material that is inadequate to withstand the forces of occlusion
How is structural durability achieved?
Occlusal reduction
Functional cusp bevel
Axial reduction
What are the finish line configurations?
Knife edge
Bevel
Chamfer
Shoulder
Bevelled shoulder
What are the expectations of crown margins to preserve the periodontium?
Smooth and fully exposed to cleaning action
Placed where dentist can finish and patient can clean them
Placed supragingivally or at gingival margin
What are the aesthetic considerations of crown preparation?
Smile lines
Material decision
What are the factors for the restoration of an endodontically treated tooth?
Post/Core gains intraradicular support for a definitive restoration
Core provides retention for a crown
Post retains core- does not strengthen or reinforce them
4-5mm root filling left apically
What are the factors for post placement?
No more than 1/3 of root width at narrowest point
1mm of remaining circumferential coronal dentine
At least 1/2 post length in the root
Minimum 1:1 post length/crown length ratio
At least 1.5mm height and width of coronal dentine
What metals can be used as a post?
Cast gold
Stainless steel
Titanium
What are the disadvantages of a metal core?
Poor aesthetics
Root fracture
Corrosion
Radiopaque
What ceramics can be used as a post?
Alumina
Zirconia
What are the advantages of ceramic posts?
High flexural strength
High fracture toughness
Favourable aesthetics
What are the disadvantages of ceramic posts?
Difficult retrievability
What types of fibre can be used as a post?
Glass
Quartz
Carbon
What are the advantages of fibre posts?
Flexible
Similar to dentine
Aesthetic
Retrievable
Bond with DBA
What are the disadvantages of fibre posts?
Radio Lucency
What is the ideal cavity preparation for amalgam?
No unsupported enamel
No sharp line/point angles
Consider use of a liner
What is the appropriate cavosurface margin for an amalgam restoration?
90 degreesq
What are the principles of cavity preparation?
Identify and remove enamel caries
Remove enamel to reveal maximal extent of the lesion at the ADJ, smooth enamel margins
Remove peripheral caries in dentine, from the ADJ then circumferentially deeper
Remove caries overlying pulp
Outline form modification: occlusion, enamel margins, requirements of restorative material
Internal design modifciation: requirements of restorative material, internal line and point angles
What are the factors contributing towards secondary caries?
Insufficient caries removal
Restoration seal is broken
Poor oral hygiene
Microleakage and no liner
What are the caries risk factors?
Clinical history
Diet
Saliva
Fluoride
Plaque control
Social history
Medical history
What are the difficulties with bonding tertiary dentine?
More sparse and irregular tubule pattern
Difficult for resin to penetrate the tubules as they are more irregular/less organised
More demineralised so etch and bond can cause breakdown
What are the reasons for dentine bond failure?
Underetch: resin tags can’t penetrate
Overreach: too deep for resin penetration
Too dry: tubules colllapse
When is flowable composite used?
Used under composite resin restoration to produce seal
What is flowable composite?
Low viscosity composite resin
What are the causes of micro leakage?
High compression factor
Poor moisture control
No liner used
Poor polymerisation
What are the determinants of cavity design?
Structure and properties of dental tissues
Disease
Properties of restorative materials
When should a lesion be restored?
Cavitated
Lesion is into dentine radiographically
Lesion is causing pulpitis
Lesion is unaesthetic
How do you decide when to remove healthy?
Restorative requirement
Margins of cavity in contact with another tooth
Margins of cavity cross an occlusal contact
What are the markers for checking the final seal of a cavity prep?
Smooth margins
Appropriate CSMA (to material)
No unsupported tooth tissue
No stress concentrators
No internal anatomy that allows adaption of the material
What are the advantages of composite?
Aesthetics
Support of remaining tissue
Command cure
No galvanism
Tooth tissue conservation
Adhesion/bonding
Low thermal conductivity
No mercury
What are the disadvantages of amalgam?
Doesn’t bond tissue
Doesn’t support teeth
Needs adequate bulk (2mm)
May need resin seal for cut dentine
More loss of tooth tissue
What are the features of an amalgam retentive cavity?
Internal dimensions greater than access to prevent dislodge
What is the ideal cavosurface margin angle for amalgam?
90 degrees or more
What is the importance of aetiology in tooth wear?
Attempt to reduce further tooth wear
Plan for contingencies and failure
Allow you to be realistic with yourself and patient
Identifies wider medical and wellbeing issues and allows sign posting
Prognostic indicator
Enhances consent process
Aids clinical diagnosis and treatment planning
What is the spectrum of attrition?
Physiological wear to bruxist
What are the modification factors for attrition?
Lack of posterior teeth
Occlusion
Restorations
Erosion and abrasion
Stress and anxiety
What are the common features of bruxism?
Significant wear throughout dentition
Repeated restoration failure
Root fractures
Often onset in early adult hood
Progressive condition
What are the features of physiological tooth wear?
Wear that you would expect given the patients afe
What features of occlusion can impact on tooth wear?
Deep overbite — affects lower incisors
Edge to edge — localised wear
What features of restorations lead to tooth wear?
Natural teeth opposed by restorations (porcelain)
What is evidence of para function without obvious wear?
Multiple cusp fractures in restored teeth
Multiple cracks around restorations
Root fractures in unrestored teeth
What are the modifying factors of erosion?
Lifestyle
Multiple factors
Amount and frequency of
Level of control
Psychosocial
What are examples of extrinsic causes of erosion?
Carbonated drinks
Sports drinks
Alcoholic acidic drinks
Citrus drinks
Acidic fruits
Acidic sweets
Pickles
Drugs- Methanthetamines
What are intrinsic causes of erosion
Eating disorders
GORD
Other medical conditions
What are the common feature of high carbonated drink intake?
Incisal erosion on upper centrals
Cupping on lower molars
Palatal erosion on upper incisors
Sensitivity
Interproximal caries and buccal white spot/brown spot caries
What are the common features of eating disorders on teeth?
Palatal erosion on upper teeth
Polished restorations
Erosion around restorations
Sensitivity
Caries
Altered taste
Halitosis
Soft tissue changes
What are examples of abrasive behaviours?
Toothbrush abrasion
Oral self harm
Tongue studs
Occupational
Unusual habits
What are the factors to consider with abrasion patients?
Localised or generalised
Frequency and duration
Bristle and toothpaste abrasivenenss
Brushing technique
Electric vs manual
Part of a combination wear problem?
Part of a stress/anxiety problem?
What combination of tooth wear is seen in alcoholism and drug use?
Erosion (ex and in)
Attrition
Abrasion
What combination of toothwear is seen in an eating disorder?
Erosion (ex and in)
Attrition
Abrasion
What combination of tooth wear is seen in a bruxist with a poor diet?
Erosion (ex)
Attrition
What combination of toothwear is seen in a bruxist with poor diet and GORD?
Erosion (intrinsic and extrinsic)
Attrition
What is the effect of combination tooth wear?
Combination has a synergistic effect on the rate of wear progression
How should you manage a tooth wear case of unknown aetiology?
Communicate a guarded prognosis
Plan warily
What factors should you consider when taking a history for a toothwear patient?
Comprehensive
Compassionate
Unconditional positive regard
Patient
What may you uncover when taking a history for a tooth wear patient?
Eating disorders
Undiagnosed diabetes
Mental health issues
GI issues
Abuse/harm/addiction
Vulerable adult/child
What are the features of an examination for a toothwear patient?
Comprehensive
Use indices
Try to relate findings to aetiology
Remember the role of caries and perio disease
What is the role of aetiology in tx planning for toothwear?
Individualised preventive plan
Reinforcement
Signposting/referral to other health and social care professionals
Review before definitive plan
What is the common preventive advice for toothwear?
Fluoride- high dose tp, alcohol free mw
Dietary mod- frequency and quantity, method of delivery, elimination and addition
Remineralisation- tooth mousse
Sugar free gum
What are the interventions you can use to control toothwear development?
Toothbrushing instruction
Splint therapy
Signposting
CBT
Hypnotherapy
Referral: GMP, Psychiatrist, social services
What is the effect of lack of posterior support on tooth wear?
Modifying factor of tooth wear
Increases severity of wear
Increases rate of progression of wear
Ultimately can lead to occlusal problems
Functional and aesthetic problems
]
What is the cause of lack of posterior support?
Denture intolerance
Denture refusal
Supervised neglect
Why should complete dentures be avoided in tooth wear patients?
Bruxism continues- fractured dentures, ridge resorption, pain, ulceration
What are the types of overdentures?
Transitional dentures
Metal based dentures
Simplifying small saddles
What is the aim of rehabilitation in toothwear patients?
Increase in OVD
What is an over denture?
Any removable prosthesis that rests on one or more remaining natural teeth, the roots of natural teeth and/or implants
What are the advantages of over dentures?
Correction of occlusion and aesthetics
Support
Tooth wear management
Preservation of ridge form
Proprioception
Denture retention
Can be used with precision attachments n
MRONJ and radiotherapy patients (avoid Xla)
Psychological benefits
Useful in elderly
Transitional
What are the disadvantages of overdentures?
Need for good OH
Increased caries/periodontal problems
Care homes
Denture fracture
Discomfort/infection
MH
Potentially more traumatic extractions
What is the OHI associated with overdentures?
Good OH
Fluoride toothpaste application to roots
Regular exams and radiographs
Denture hygiene
What is the result of transitional dentures?
Increase OVD where there is poor posterior support to create space for restorations
What do transitional dentures explore?
If the patient can cope with transitional dentures and increased OVD
When would you need a metal based denture?
Bruxism
What do overlay dentures do?
Overlays teeth to protect remaining teeth
What circumstances would you conform to the existing occlusion?
Stable occlusion
Sufficient index teeth
Ensure prosthesis/restoration does not alter occlusion
What circumstances would you change/rehabilitate the occlusion?
Unstable occlusion
Lack of sufficient index teeth
What factors are involved in planning for toothwear cases?
Impressions and face bow
Mounted articulated casts on semi-adjustable + or - surveying
High quality interocclusal records- with or without increasing the OVD
Diagnostic wax ups
Stents- mock up - temporaries for build ups (aids consent)
Temporary (transitional) dentures
Clinical photos
Radiogrpahs
When would you chose a confirmative approach?
Stable occlusion
Sufficient index teeth
When would you chose a rehabilitative approach?
Unstable occlusion
Lack of sufficient index teeth
Challenging to record occlusion
What planning is important in toothwear cases?
Impressions and face bow
Mounted articulated casts on semi-adjustable + or - surveying
High occlusal record- with or without increasing the OVD
Diagnostic wax ups
Stents/mock ups/temporaries for build ups (aids consent)
Temporary (transition) dentures
Clinical photographs
When would you carry out tooth preparation in tooth wear?
Lack of occlusion-gingival height
Lack of occlusal space
Severely compromised teeth
How can you modify teeth to create retention and resistance in small teeth?
Materials
Grooves
Inlays
Ferrule
Parallel preps
Margins and occluding surfaces
Cores
Electrosurgery
Surgical crown lengthening
What is the function of inlays and grooves?
Enhance resistance form by reducing the radius of rotation.
Should be placed in the long axis of teeth
Why is dental demolition common?
Heavily restored teeth
Previous failure
Small teeth
High occlusal loads
What are the features of operator safety in dental demolition?
Adequate eye protection
Surgical gloves
What are the features of patient safety in dental demolition?
Eye protection
Airway protection
Comfort- suction
What bur should be used to cut porcelain?
Coarse diamond
What bur should be used to cut metal?
Gold cutting
What may you need to use in problem dental demolition cases?
Sliding hammers +/-matrices
Cut occlusal and palatal surfaces
Enamel chisel
What is the basic technique for dental demolition of indirect restorations?
Plan with contingencies and communication with patient
Pre-op impression necessary for temporary
Try vertical cuts first, if bridge stays intact may be able to use as a temporary
Section abutments apart trying to keep intact useful ones
Critically appraise cores
What is the basic technique for repeat endo?
Conventional files, GT files, GG burs
Rubber dam
Eucalyptus/turpetine oils
What should you use for problem repeat endo cases?
Ultrasonic instruments/magnification
High risk of instrument fracture
What factors should you consider in regard to post removal?
Case assessment
Risk of fracture
Ease of removal - length/taper/surface
Contingency plan for fracture
Other pathology with tooth
What should you use for the removal of fractured posts?
Masseran kit
Ultrasonics
What is a failing dentition?
A dentition where deteriorating teeth, restorations or oral health or a combination of issues means loss of adequate basic oral function such as mastication and acceptable aesthetics is inevitable if left untreated
What are the keys to success when managing dental failure?
Comprehensive history and exam
Thorough planning
Seek advice if needed
Prevention
Avoid over ambition tx
Effective communication
Decision making and tx planning around basic principles
Keep plans simple
Have an effective maintenance strategy and regularly re-assess the situation
What are the main preventative aspects of a failed dentition?
Basic oral health messages
Individualised oral hygiene instruments
Individualised dietary advice
Individualised fluoride regime
Individualised habit advice and management/referral to other health and social care professionals for advice/safeguarding issues
Information provision and documentation in the records
Assess response to preventive and oral health measures before embarking on advanced treatment
What are the features of effective communication in managing failure?
Effective listening
Honesty and transparency
Take into account patients wishes
Addressing difficult issues- oral hygiene, habits, failing restorations, previous treatment,
Seek advice
Giving patients a reality check
Documenting discussions
Be assertive but compassionate
Time and patience
Avoid patient led tc
Holistic approach
Breaking Bad News protocol: (SPIKES)
Set up the interview- mental and physical preparation
Perception- assess what the patient knows about the medical condition
Invitation- ask how much they want to know
Knowledge; give medical facts
Emotion- respond to patients emotion
Strategy and Summary- negotiate a concrete follow up step
What is osseointegration?
A direct functional and structural connection between a load bearing dental implant and living (organised bone)
What are the stages of osseointegration?
Primary and Secondary
What is primary osseointegration?
Implant is anchored in bone due to frictional forces provided between osteotomy and dental implant design features
What is secondary osseointegration?
The process of a functional connection between bone and a dental implant. Living bone grows on the surface of a dental implant
What kind of healing follows implant insertion?
Immediately after implant installation:
Granulation tissue in wound chamber (days)
Immature (woven bone) - (weeks)
Mature lamellar bone (months)
Collagen orientation is present at around 4 weeks and mature tissue attachment 6-8 weeks
What are the features of supra crestal soft tissue?
More fibroblast
Less collagen
Collagen fibres are orientated perpendicular to root surface
What are the features of sub-crestal bone?
Tooth anchored to bone by periodontal complex (bone, pdl, cementum)
Capable of physiologic adaption
‘Resillent’ tissue attachment
What are the features of supra-crestal tissue when an implant is present?
More collagen
Less fibroblasts
Collagen fibres orientation parallel to implant crown
What are the features of sub-crestal bone when an implant is present?
Implant anchored to bone by direct functional contact
No physiologic adaption present
Rigid connection
What are the materials for dental implants?
Titanium
Titanium Zirconium
Ceramic Implant
What are the features of titanium dental implants?
Commercially pure type 4 titanium
>85% to produce titanium dioxide
What are the features of titanium zirconia?
85% Ti, 15% Zr
Increased strength compared to Ti
What are the features of ceramic implants?
Yittra stabilised zirconia
Marked as a ceramic impant
Non-metallic coloured
High survival at 1 and 2 years
What is the selection criteria for implants length/diameter?
Site
Indication
Local anatomy
What are the features of increased survival in dental implants?
Narrow diameter
Short <10mm
What are the options for implant surface treatments?
Machined/turned
Roughness
Surface treatment
What are the options for roughness in regard to implants?
Smooth [0-0.5um]
Mild [0.5-1um]
Moderate [1-2um]
Rough [>2um]
What types of surface treatments are available?
Sand blasting
Acid etch
Plasma spray
What is the purpose of an implant?
To replace missing teeth functionally, aesthetically and psychologically
What are the primary aims of a dental implant?
Replace missing teeth with aesthetic, functional and predicable restoration
Low rate of complications during healing and maintenance period
Long term stability
What are the features of an assessment for dental implant placement?
Prosthetic value of the tooth
Periodontal status
Endodontic status
What are the factors of patient assessment for implant in regard to patient level?
Presenting complaint
Motivation
Medical history
Dental history
Social history
Age/skeletal maturity
What medical conditions would render a patient unsuitable for a prolonged treatments such as implants?
ASA classification
Haematological
What medical conditions may affect the survival or success of dental implants?
Medication; SSRIs, PPIs, bisphosphonates, steroids
Radiotherapy
Poorly controlled diabetes
Cardiovascular disease
What SDCEP guidelines are for MRONJ?
Oral Health Management of Patients at Risk of Medication-Related Osteonecrosis of the Jaw
What is the effect of smoking on implants?
Vascularity
Fibroblasts/osteoblast function
PMN function
What are the features of dental history that are relevant for implants?
Patient attendance
Motivation
Self performed plaque control
What treatment has the patient accepted in the past
Are they suitable for surgical procedures
Are they a bruxist
What are the risks associated with placing implants are associated who are not skeletally mature?
Relative infra-occlusion
Suboptimal aesthetics
Occlusal disharmony
Implant fenestration
Describe a high, medium and low smile line:
High- >2mm soft tissue show
Medium <2mm soft tissue show
Low- lip covers >25% of teeth
What extra oral features are relevant for implant placement?
Skeletal relationship
Presence of incisal cants
Presence of gingival cants
Width of aesthetic zone
What are the types of gingival biotype?
Thick, low scalloped
Medium thick, medium scalloped
Thin high scalloped
What are the effects of bone crest to contact point?
The distance from the bone crest to the adjacent contact point will determine the presence of the adjacent papilla
What are the pink aesthetics?
M-D papilla
Gingival zenith
Mucosal contour/deficiency
ST colour and texture
What is the effect of a too wide edentulous space when planning implants?
Challenge to fill place
Where to leave residual space
What is the effect of a too narrow edentulous space when planning implants?
Risk of damage to adjacent teeth
Risk of necrosis of bone between teeth and implant
Will have significant effect on soft tissue aesthetic
What is the necessary width for a tooth?
7mm
What is the relevant maxilla anatomy in regard to implants?
Maxillary sinus
Nasal floor
Naso-palatine canal
Infra-orbital canal
What is the relevant mandible anatomy in regard to implants?
Inferior alveolar canal
Mental foramen
Incisive canal
Lingual perforating vessels
Submandibular fossa
What should you consider in 3D implant positioning?
Mesio-distal positioning
Mesio-distal orientation
Bucco-palatal positioning
Bucco-palatal orientation
Apico-coronal postion
What does 3D implant positioning depend on?
Implant system
Proposed gingival margin
Local anatomy
Prosthetic plan
What are the mesio-distal implant considerations?
Should be placed a safe margin from adjacent teeth: lowers risk of damage to adjacent teeth, lowers risk of bone necrosis and ST defect between implants and teeth
Minimum of 1.5mm
What are the bucco-palatal implant considerations?
Positioning
Angulation/orientation
Depends on cement retained or screw retained
Aim for >1mm of bone labially or >2mm hard tissue/soft tissue labial to implant
When should a guided bone regeneration be considered for implants?
Dehiscence
Fennestration
Inadequate contour
What are the apico-coronal positioning features for implants?
relative to the gingival margin
depends on whether a tissue or bone level implant is chosen
Bone level implants are used in the anterior maxilla
What is the implant placement protocol?
Immediate implant placement
Early implant placement with soft tissue healing (4-6 weeks)
Early implant placement with partial bone healing (12-16 weeks)
Late implant placement in healed sites (>6 months)
What tools can aid implant planning?
Study models
Diagnostic wax ups
Surgical template
Essex (provisional)
Clinical photos
CBCT
Surgical guide
What are examples of implant retained prosthesis?
Removable: stud, bar and magnet retained
Fixed: screw or cement retained
What are examples of over denture attachments?
Retentive anchor
Locator
Bar-borne with synOcta
What are the components of open tray impression?
Impression post
Guide screw
What are the benefits of open tray impression?
Colour coded components correspond to prosthetic connection
High precision impression
Clear cut tactile response for accurate positioning
Guide screw can be tightened by hand or with the SCS screwdriver
What are the components of a closed tray impression?
Cap (polymer)
Post
Screw
What are the benefits of a closed tray impression?
Colour coded components correspond to prosthetic connection
No addition preparation of tray
High precision impression
Clear cut tactile response for accurate positioning
What are the factors associated with screw retained implant prosthesis?
Ideal implant position
Retrievable
Retention is possible even below 4mm abutment height
Occlusal interference possible
More susceptible to porcelain and screw fracture
More difficult to access
More expensive
Better tissue response
What are the factors associated with cement retained implant prosthesis?
More universal
Retrievability is possible but unpredictable
Needs >5mm abutment height for retention
Less occlusal interference
More susceptible to peri-implant inflammation due to excess cement
Easier to access
Less expensive
Easier to fabricate
What are the components of the pink aesthetic score?
Mesial papilla
Distal papilla
Soft tissue level
Soft tissue contour
Alveolar process deficiency
Soft tissue colour
Soft tissue texture
What are common causes of compromised tissue sites?
Post extraction defects
Trauma
Hypodontia
Periodontal disease
Thin biotype
