Clinical stuff Flashcards
Indications for endodontics
[8]
Irreversible pulpitis
Periapical pathology
Trauma
- High risk of pulp sclerosis which would make future RCT v difficult. Consider elective RCT.
Overdenture
Periodontal disease
- Peri-endo lesions (can resect the involved root and RCT the other roots)
Post retained restorations
- But will be elective RCT on a vital tooth so consider a lot before doing this
Teeth w doubtful pulps
- Esp if planning an indirect (1 in 5 fail anyway)
ORN or MRONJ risk
Contraindications to RCT
[8]
MH - can they withstand long treatment and lie back in chair e.g. epilepsy, age, joint issue in neck?
Limited mouth opening
- after radiotherapy, TMD, microstomia
Uncompliant pt/poor OH
Tooth isn’t restorable
Non-functioning tooth
Root fractures
Periodontally involved e.g. stage 2+ mobile
Anatomical variations e.g. v curved roots.
Types of root resporption
Cervical external resorption
External replacement resorption
Internal resorption
External cervical resorption
Due to trauma, ortho, bleaching + unknown
Starts at cervical area - root replaced by granulation tissue
Clinically = a catch and pink granulation tissue showing
Rad/CBCT = moth eaten area
If it extends into the pulp it will cause pulp symptoms
Diagnose early, explore and repair surgically and do RCT if needed
External replacement resorption
Due to trauma
PDL and root replaced with bone gradually - all of root surface.
Ankylosis and root turns into bone eventually and crown falls off.
Process happens quicker in children.
Clinically = submerged, metallic noise on percussion, v stiff teeth
Rad = moth eaten area but all around the tooth
Can be self limiting but usually not - no treatment but can do implants after bc lots of bone
Internal resorption
Due to history of/chronic pulpitis
Starts in pulp and expands.
Process continues until pulp becomes non-vital so diagnose early and RCT will stop the process and preserve tooth.
Clinically = pulpitis symptoms and pink spot if happening coronally
Rad = ovoid radiolucency in root canal
GP phases
Phase 1 - Beta = 42 degrees - Alpha = 42-49 degrees Phase 2 - Amorphous = 49 degrees. Can flow
Why use endo-sealers [3]
Lubricate instruments
Fill small defects/lateral canals
Seal obturating material
Types of endo-sealers [4]
Zinc Oxide Eugenol
Calcium hydroxide - less toxic but also less antibacterial than ZnO
MTA - hard to remove for retreatment
Resin-based - bonds to dentine but hard to remove for retreatment
Types of obturation techniques [7]
Cold lateral condensation Warm lateral condensation Single file Thermomechanical technique Warm vertical condensation Carrier-based technique Apical plug
Cold lateral condensation (cons)
Slow and technique sensitive
Doesn’t fill irregularities
Warm lateral condensation (technique)
Use k-file in ultrasonic and insert into the canal with master GP and heat it up to allow it to spread.
Accessory points are inserted like normal.
Single cone endo obturation (technique, pros and cons)
Like ProTaper
Easy and quick
But master GP needs to be exactly the same flare and size of prep files.
Doesn’t fill irregularities
Thermomechanical endo obturation (technique, pros and cons)
H files in the slow handpiece placed 3-4 apical from working length
GP heated up to allow it to soften and spread apically and laterally
But H files can snap and GP can extrude beyond apex.
warm vertical condensation (technique, pros and cons)
Apical plug 3-4mm from working length
- Normal master GP chosen
- Plugger that stops 3-4mm short heated and inserted into the GP in 1 motion and wait until it reaches at least 4mm (10s to stop shrinkage of GP)
- Remove and excess GP
Backfill the rest of the canal
- In 3-4mm bursts
- Compact after each burst
Easy, quick
Fills irregularities and lateral canals really well
Needs expensive and special equipment
Carrier-based method (technique, pros and cons)
GP around a heat resistant carrier e.g. plastic or heat resistant GP.
Choose the master GP and remove any excess GP that isn’t supported by the carrier as this will be hard to control.
Heat and insert into the canal in 1 quick motion
- Technique sensitive
- Hard to re-treat or place a post if used a plastic carrier.
- But easy to learn and good 3D obturation
Apical barrier obturation for open apices (technique)
For immature apices or apices wider than 0.7mm
Apical plug (MTA or Biodentine) and then backfill
Minimal prep needed bc canal is already wide, careful not to extrude irrigants.
Indications for surgical endodontics [4]
Can’t do regular RCT/re-treatment for PAP but need to save tooth
Persistant apical periodontitis
Apical surgery
Corrective surgery when you need direct visualisation e.g. perforation, GP extruding, external resorption, root resection
Types/reasons for persistent apical periodontitis [4]
Foreign material e.g. extruded GP
Cyst
Cholesterol crystals
Scar tissue formation
Contraindications to surgical endodontics [5]
MH - severe bleeding disorders, MRONJ/ORN risk, can’t withstand long surgery
Unrestorable tooth
Bone loss (apical surgery reduces crown: root ratio)
Poor surgical access
If other options are available
Surgical endodontics objectives [4]
Remove apical infection
Clean canal in a coronal direction
Seal apical portion and place filling in the canal
Allow PAP and soft tissues to heal
Surgical steps for surgical endodontics (tooth apical surgery) (brief) [11]
- NSAID and Corsodyl pre-surgery medication
- Analgesia
- Flap
- Bone removal/osteotomy
- Currettage of peri-radicular lesion
- 90-degree root apical resection
- Use special ultra-sonic equipment to debride root apex and clean/prepare canal 3-4mm at least
- Haemostasis and moisture control using epinephrine pellets
- Place a filling and seal in the canal (MTA, Biodentine)
- Suture
- POI
Incision/flap types for endodontic surgery
- Crevicular/sulcular flap with a relieving incision - but at risk for cervical recession
- Sub-gingival flap w 2 relieving incisions for crowns to avoid recession
- Papilla base incisions to leave papilla and reduce risk of recession here
Osteotomy for surgical endodontics - air rota used and why
Not contra-angle bc air is blown into the surgical field and can cause surgical emphysema and the angle is wrong.
Use a surgical air rota (correct angle and air not blown into surgical field)
POIG for surgical endodontics
Analgesia
Corsodyl to keep it clean
Usual bleeding, pain, infection post-op warnings
Stitches removed after 2-4 days
Icepacks
- Antibiotics only if worried about immunosuppressed pt
Examples of tricalcium silicates
MTA (mineral tri-oxide aggregate)
Biodentine
MTA components [4]
Medical-grade cement
With contaminants e.g. lead, arsenic removed
Radiopaque material added
Calcium Sulphate added to control the setting time
MTA benefits [6]
Non-resorptive No leakage Non-toxic Alkaline V bio-compatible (PDL and cementum can form onto it) Stimulates tertiary dentine
MTA or Biodentine uses [4]
Pulp cap Repairing perforations Repairing resorption defects Root apex surgery/apical plug Biodentine - stronger so can be used to bulk fill/as an intermediate and replaces the dentine
How to use MTA [4]
Mix with sterile water
Need to keep adding water bc the mix will dry out as you use it
If internal restoration then it will need some wet pellets to be placed next to it and left until the material has hardened.
Takes 3-4h for initial hardening, and then will continue getting stronger over 3 weeks.
Disadvantages of MTA [5]
Not that strong so shouldn’t be used for bulk fillings
Takes a long time to set and might fall out before it has set
Difficult working times/conditions
Expensive
Acidic environment affects setting so can’t be used if there’s infection
MTA vs Dycal for pulp caps
MTA studies show a continuous dentine bridge/no gap
Biodentine components [3]
Tri-Calcium Silicate/similar to MTA but add the following instead of water:
Calcium Chloride added as an accelerator
Polymer to quicken setting time
Advantages of Biodentine [5+]
Non-toxic, Biocompatible, etc.
Goes into dentine tubules and forms a plug (micromechanical retention)
When it has set it’s strong like dentine so can be used for bulk fillings (compressive strength) - 2 stage restoration w the Biodentine left behind like a core
No shrinkage = no leakage
Forms tertiary dentine
Quicker setting time (9-12mins)
Biodentine VS MTA
Can be used for bulk fillings bc greater compressive strength
Quicker setting time
Types of endodontic outcomes [5]
Strict success = no symptoms, functioning tooth, no PAP
Loose success = no symptoms, functioning tooth, PAP is smaller/not increased in size (4 years)
Survival = functioning tooth, no symptoms
- OR/better -
Favourable outcome = No PAP, symptoms and functioning tooth
Uncertain outcome = PAP hasn’t increased in size - monitor for 4 years
Unfavourable outcome = non-functioning tooth, symptoms, new/larger/non-healing PAP after 4 years
Favourable endodontic outcome
Favourable outcome = No PAP, symptoms and functioning tooth
Uncertain endodontic outcome
Uncertain outcome = PAP hasn’t increased in size - monitor for 4 years
Unfavourable endodontic outcome
Unfavourable outcome = non-functioning tooth, symptoms, new/larger/non-healing PAP after 4 years
What is the endodontic outcome affected by [5]
PAP - larger >5mm means it’s well established and more bacteria
Necrotic pulp or infected pulp
Root canal filling - voids, too short or overextended
Coronal seal - no voids, caries, etc.
Endodontic review appointment - what do you do/ask? [4]
Symptoms/pain
Clinical exam
- Coronal seal, caries, perio, TTP, fractures
Radiographic exam
- Coronal seal, caries, perio/bone levels, root canal filling, PAP size
Definitive restoration
- ASAP after symptoms have resolved or sooner if concerned about tooth
Reasons for pain post-endo [5]
Failed RCT Neurogenic pain - nerves hypersensitive after PAP Non-odontogenic pain Fractured tooth Occlusal force
Management of failure of RCT (options) [4]
Monitor
- If the tooth is asymptomatic, functioning and stable then can give this as an option
- But warn pt of risk of flare-up, may not be able to save the tooth later on, need regular monitoring
XLA
Re-RCT
- tooth needs to be restorable. More complicated and less successful.
Apical surgery -
Fit appointment for indirects - stages
- Check the lab work and condition of the indirect
- Remove temporary
- Try in
- Cement
Fit appointment for indirects - step 1: checking the lab work and condition of the indirect
- Check cast/die for any wear or broken bits as this may affect the fit
- Check fitting surface of indirect
- Check polished surface of indirect and ICP/eccentric movement
- Check for any notes from the lab
Fit appointment for indirects - step 2: removing the temporary
- Check temporary for any signs of wear, fractures, tooth drifting of other teeth (may happen if temp is lost)
- Check function e.g. speech
- Remove temporary and clean tooth using pumice. Don’t damage tooth or soft tissues.
Fit appointment for indirects - step 3: try in of permanent
- Check proximal contacts
- Check margins
- Adjust fitting surface if not seating properly using occlude spray.
- Check occlusal contacts
Signs of correct seating of indirects
- No gaps at margins (will need to be sent back to lab)
- Seats without any rocking
- ICP contacts and eccentric contacts but no interfering contacts
- Marginal ridges of adjacent teeth are level
- Aesthetics
- Speech
Fit appointment for indirects - step 4: final cementation
- Clean, dry, isolate tooth
- Use correct cement
- Seat fully
- Remove excess
- Check occlusion
- Give POI and OHI.
Types of cements for indirect restorations
Temporary
- Zinc Oxide Eugenol (TempBond)
- Non-eugenol (TempBond NE) - bc Eugenol affects the setting of permanent resin-based cements.
- Soothes the pulp and soluble
Permanent
- Zinc phosphate/carboxylate = outdated bc soluble, exothermic acid-based reaction can irritate pulp
- GIC
- RMGIC/RelyX luting
- Resin-based = self etch or total-etch
For metal = any
For ceramics/composites = bonding resin-based for more strength
Zirconia/alumina = GIC/RMGIC
Luting adhesive cements = chemical adhesion + luting. It’s stronger so for when the material or margins are weaker (composite, resin-based, ceramics).
Luting = just filling the space. For metal or complete zirconia/alumina ceramics bc can’t bond
Ideal properties of permanent indirect restoration cements
Insoluble High tensile and compressive strength Bonds to tooth and restorative material Radiopaque No marginal breakdown Long working time but fast setting Low viscosity Cariostatic Non-toxic/biocompatible
Total etch cement for indirects
For ceramic indirect that can be etched by lab e.g. no zirconia or alumina
- Etch tooth w phosphoric acid and dentine bonding agent
- Etch fitting surface of indirect in lab
- Total etch cement + silane coupling agent on indirect
- Auto-cure, light-cure or dual-cure
Bonds to ceramic and tooth
Strong
low solubility
Self etch cement for indirects
Don’t need to etch dentine and used for when u can’t etch ceramic e.g. zirconia or alumina.
Bonds and micromechanical retention to ceramic and tooth
Strong
low solubility
GIC as a permanent indirect cement
Acid soluble so margin breaks down
Post Op sensitivity
Strong
Fluoride releasing
Adhesive
RelyX Luting/RMGIC as a permanent indirect cement
For metal-based and zirconia indirects Fluoride releasing Micromechanical retention Strong Low solubility Adhesion to tooth Low post-op sensitivity Doesn't need moisture control to use - But absorbs water over time and expands = can't be used for ceramics
Things to consider before permanently restoring RCT teeth [4]
Asymptomatic?
How good is the RCT
Can the tooth be accessed again if re-treatment is needed?
2+ surfaces lost means cuspal coverage is needed
Why provide permanent restoration after RCT [4]
To restore aesthetics, function
Provide the best coronal seal
Strengthen tooth
Coronal restorative material ideal properties [9]
Easy to place
Can be removed/accessed if re-treatment needed
Flexural, compressive and tensile strength
Similar elastic modulus and thermal expansion as tooth/dentine
Radiopaque
Retentive
Adhesive
Core-build up considerations after RCT [5]
Amalgam isn’t used anymore
Composite = good bond, compressive and tensile strengths
GIC = good bond but weak and brittle
Cut down root canal slight and use this for retention
Why provide posts after RCT
Posts provide more retention for coronal restoration/core and allow forces/stress to be spread axially. Not needed for posterior teeth bc large pulp chamber provides retention.
Types of posts (after RCT)
Materials
- Prefabricated for round preparations
- Cast for irregular shaped
- Prefabricated = Stainless steel or composite resin fibre
- Cast = metal or ni-cr
How to provide a post after RCT
Remove 2/3rd of root canal/leave 3-4mm apically
- longer means more retention and more stress dissipation but too long can affect the apical seal
Place prefabricated or cast core
- Ferrule (1.5mm of dentine between core and crown margins) for lateral stress dissipation
- Parallel sides better (taper can cause root fractures)
- Thin core to preserve dentine (but not too thin that it isn’t retentive/core breaks)
- Anti-rotation usually comes from irregularly shaped pulp chamber
Cement
- Micromechanical retention by roughening the core surface
- Adhesive luting cement that bonds to dentine
- Passive retention > active retention (like screws)
Para post system for providing posts after RCT
Prepare canal using special burs and use corresponding sized pre-fabricated post.
Can build up a core around it and then plan for a crown
What is an inlay/onlay and when to use (indications)
Intra-coronal restoration or + cuspal coverage
Used to improve strength and structure of the tooth
Indications
- When you can’t use amalgam (mercury, lichenoid reaction) or composite (moisture control, big filling)
- When you want to place a better restoration but more conservative than a full-coverage crown
- Low caries rate and small MO/DO/MOD
- Low caries rate and RCT, or loss of 2+ tooth surfaces but buccal and lingual walls intact
- Onlay for when you’re worried about wedging forces causing fracture (happens to big inlays)
Contraindications for inlays/onlays
High caries rate
Heavy occlusal forces or parafunction e.g. bruxism
Types of inlays/onlays
Gold
Ceramic
Composite resin
Gold inlays/onlays
Great physical properties Conservative prep Minimal wear and corrosion Durable - Poor aesthetics
Ceramic inlays/onlays
Strong so v little wear
Aesthetic
- Luting agent can wear down over time and cause marginal leakage
- Can be brittle if too thin (<2mm)
Preparation for inlay/onlay (metal and ceramic)
1.5mm occlusal reduction
2mm cusp reduction
Smooth internal angles, divergent box walls
Isthmus should be <1/3 intercuspal width
Interproximal box width of 1mm
Margins on tooth tissue
No tapered margins (ceramic is brittle if thin)
No undercuts
Occlusal contacts shouldn’t be on margins
Cementation of inlays/onlays
Should be done under a rubber dam
Ceramic = adhesive resin-based cement e.g. total-etch, sandblasting/HF acid and silane coupling agent
Gold = luting cement or adhesive e.g. Panavia/self-etch systems
Temporisation for inlays/onlays
Direct with a composite resin e.g. ProTemp - no imp or cement needed
Indirect - lab or chairside e.g. ProTemp. Take pre-op impression and use TempBond NE
How do inlays/onlays fail?
Marginal breakdown/leakage
Fracture of tooth or restoration
Types of bridges [4]
Maryland/resin-bonded
Fixed-Fixed
Fixed-Cantilever
Rochette (hole son the backing framework)
Considerations when designing bridges [7]
Abutment teeth prognosis - PA health - Periodontal health - Restorative Crown:root ratio Crown size/Surface area Occlusal forces, parafunction, excursive contacts Over-erupted teeth, tilted, rotated Appearances Cleanability
Ideal abutment teeth for bridges [6]
Big surface area for enamel bonding No PAP, caries, etc. - good prognosis Periodontal health and good bone levels Not over-erupted, tilted or rotated Good crown:root ratio Not RCT
Fixed-cantilever bridges vs Fixed-Fixed
Fixed-fixed - one will always debond bc of difference forces and each abutment will flex differently.
If one debonds, the bridge won’t fall off but that abutment tooth becomes plaque retentive and quickly develops caries.
Therefore, cantilever are more retentive and more hygienic.
Only use fixed-fixed for lower anterior teeth
Anterior resin-bonded bridge: preparation elements [5]
Minimal reduction and chamfer
Cingulum rest
Parallel mesial distal grooves - can connect them with an occlusal bar.
Resin-bonded bridge: framework design considerations [7]
Maximum surface area for enamel bonding without compromising aesthetics and gingival health.
Thicker means less likely to flex and debond - minimum 0.8mm for posterior teeth.
Thicker at connector to avoid flexion and there should be no contacts here.
Height of connector should be at least 1/2 of the pontic height
Types of alloys used for bridge frameworks
Gold alloys
Ni-Cr
How do resin-bonded bridges fail [3]
Debond and fall off (cantilever)
Debond and caries (fixed-fixed)
Aesthetic failure
Conventional bridges disadvantages [2]
More destructive and poorer prognosis - use cantilever adhesive.
Primary occlusal trauma
Occlusal trauma to teeth with normal periodontal height, resulting in widening of the PDL
Secondary Occlusal trauma
Occlusal trauma to teeth with a reduced periodontium, resulting in widening of the PDL space
Causes of occlusal trauma [5]
Excessive and abnormal forces
- Parafunction
- High restorations/premature contacts
- Drifted teeth
- Loss of posterior teeth
Clinical features of occlusal trauma [6]
Pain Mobility Teeth drifting Tooth wear TMD Fremitus (tooth movement when functional occlusal forces applied)
What is fremitus
Tooth movement when functional occlusal forces applied
Types of occlusal forces [2]
Orthodontic = unilateral continuous force Jiggling-type = from different directions
Consequences of increased jiggling-type forces (occlusal trauma) on periodontium
Healthy perio i.e. no active bone loss or inflammatory disease =
- widening of PDL space
- Physiological mobility (adaptive)
- No pocketing
Unhealthy periodontium e.g. active bone loss, perio =
- Enhanced rate of disease progression (pocketing and bone loss)
- Pathological mobility (tooth migration, fremitus, pain)
Management of teeth with occlusal trauma
- physiological mobility
Healthy periodontium, physiological mobility - no active disease (may have had previous perio and bone loss but stable now)
- Doesn’t need treatment if asymptomatic
- Can splint if mobile or symptomatic
Management of teeth with occlusal trauma
- Pathological mobility
OHE
Perio treatment - non-surgical or surgical
Splint teeth
XLA poor prognosis teeth
Splints for teeth with mobility and different types
Splints should keep the teeth rigid, include as many stable non-mobile teeth as possible, be hygienic and not affect occlusion or soft tissues.
Types:
- Temporary (few months during healing period)
- Semi-permanent (before and during regenerative surgery)
- Permanent
- Fixed - indirect (cast in a lab and cemented to palatal/lingual surface of the teeth) or direct (composite bonding, ortho wire)
- Removable - like a Michigan stabilisation splint, for pt with TMD or parafunctional habits
What does PMPR remove [3]
Inflammation tissue (granulation tissue) Calculus/bacteria/plaque Thin layer of cementum with endotoxins
Disadvantages of PMPR [4]
Not good visualisation/poor access
Can have acute periodontal infections (abscesses)
Doesn’t always work
Can’t visualise and treat bony defects
Aims of periodontal surgery/indications [8]
Gain better access/visualisation
- To repair bony defects
- To do PMPR and remove granulation tissue
Bone contouring
Crown lengthening procedures/access root surface for restorative work
Guided tissue regeneration/re-attachment
Reduce pockets
Reduce gingival overgrowth e.g. gingival hyperplasia or false pocketing
Considerations before doing periodontal surgery on a patient [5]
Has non-surgical periodontal therapy been done (PMPR, antibiotics, etc)
Is the patient suitable?
- MH - bleeding, bisphosphonates,
- OHE, stable periodontal health, compliant
Informed consent - the risk of sensitivity, recession
Restorative strategy - prognosis of the teeth and any other work that needs doing
Gingivectomy - indications and requirements [4]
Gingival hyperplasia or false pocketing
But need to have enough attached keratinised gingiva
If don’t have enough attached keratinised gingiva, then will need to do an apically repositioned flap
Gingivectomy steps [6]
- Analgesics
- Take pocket measurements and mark with a bleeding point where you want to do the incision (GOLDMAN procedure)
- External bevel incision at bleeding point, follow gingival contours
- Debridement of the root surface
- Haemostasis and packs
- Post-operative instructions and review
Type of healing with gingivectomy procedure and ideal outcomes
Secondary healing
Epithelialisation from islets in remaining gingivae
- Normal pocket depth, aesthetics and restore ideal gingival contours
Periodontal surgery - different flap procedures (indications, pros, cons) - pedicle flaps (attached and being repositioned))
Replacement flap - if you want it to be in the same place
- For inflammatory perio disease or bone defects
Or an apically repositioned flap
- But will expose some root = poorer aesthetics, sensitivity
- For when there’s pocketing, false pocketing or inflammation but not enough attached gingiva for gingivectomy
- To reduce the pocket and reduce inflammation
- Or for crown lengthening surgery (but will need to remove some bone too)
Or coronally/laterally repositioned flap - for recession defects
Periodontal surgery replacement flap - steps [6]
- LA
- Internal bevel 1mm below the gingival margin, almost parallel to the long axis of the tooth + a crevicular incision
- follow gingival contours and do the same thing palatally if needed or just a gingivectomy palatally bc thicker
- Remove the inflamed coronal part of the gingiva
- Do any RSD/GTR/fixing bone defects
- Suture the buccal bit to the palatal side
Healing outcomes of flap procedures (periodontal surgery) [3]
Normal indices and periodontal health
No increase in mobility
Improved attachment, bone levels, contours
Good aesthetics
Periodontal surgery: raising a replacement flap for access - indications [5]
Access root surface for restorative work Apical surgery, root resection, root division etc. Repair bony defects or furcation defects Guided tissue regeneration Bone contouring (osteoplasty)
Modified Widman flap [4] - for replacement flaps
1mm below gingival margin instead of 2mm
Preserve dental papilla
Incision parallel to bone / in an apical direct
- Preserves gingival tissue more to reduce recession and improve aesthetics.
Frenectomy - indications [3]
Attached to dental papilla or v prominent or causing problems.
Post-operative instructions and procedure after periodontal surgery
Analgesia, NSAIDs, OHE, chlorhexadine MW
Liquid diet for at least 1 week
No brushing or eating in the area for 2-3 weeks (use MW 2x daily)
Sutures from donor area removed 1 week after
Sutures from recipient area removed 4 weeks after
Regular OH monitoring
1-week review - OH and donor sutures removed
1-month review - OH and recipient sutures
3-month review (check probing, or delay if GTR)
6-month review (checking indices)
9-month review (bone improvement can be seen on Xrays)
12-month review = all healing and creeping attachment should be done
Stages of wound healing
- Haemostasis (hours-days)
- Blood clot and coagulation cascade (fibrin) - Inflammation (2-10 days)
- Acute = neutrophils
- Chronic = phagocytes (to get rid of old WBC)
- Fibroblasts and endothelial cells are brought to the site - Granulation/proliferation (days - month)
- Collagen
- Angiogenesis
- cell-to-cell contraction closes the wound
- Precursor cells e.g. Ob brought to site - Maturation (week-months)
- Remodelling
- Extra blood vessels removed
Types of healing
- Regeneration (normal tissue architecture and function, need precursor cells)
- Repair (not complete healing, fibrosis/scarring)
- Primary intention (surgical incisions, sutures, minimal cell/tissue damage)
- Secondary intention (larger tissue damage and cells lost, infection, scarring)
Factors affecting healing by regeneration vs repair - local and systemic
Local
- Blood supply to the area
- Infection
- Surgical closure
- Size and type of wound
- Radiation
Systemic
- Bleeding disorder, diabetes,
- Medications e.g. bisphosphonates
- Age, stress, hormones, nutrition, smoking
Histological patterns of healing after periodontal surgery [6]
- No healing
- Repair - long junctional epithelium (LJE)
- Bone formation but no PDL cells/CT - might have LJE
- Bone formation with CT attaching to tooth +/- existing PDL tissue
- Bone forming onto tooth + replacement resorption (ankylosis)
- Complete regeneration
Complications of periodontal surgery (during procedure, short and long term)
During
- Pain, bleeding
- damage to the flap
- Apex exposed and loss of vitality
Short-term
- Pain, bleeding
- Infection
- Dysthesia
- Sensitivity
Long-term
- Recession
- Sensitivity
- Dysthesia
- Poor aesthetics
Pedicle flaps (periodontal surgery) healing
By primary intention
Regeneration (CT, PDL inserts onto tooth, bone levels improve) or repair by long junctional epithelium
Regenerative periodontal surgery - types of bone substitutes [7]
Osteoinductive - induces bone
Osteoconductive - scaffold
Osteogenic - turns into bone
Autogenous graft
Xenograft (from animal)
- Bone-oss = has pores that stabilise clot and attracts Ob and bone-forming substances so bone laid down in these pores (scaffold)
- Boneglass = (like HAP) attracts Ob and bone-forming substances so the bone is laid down around the particles (scaffold and Osseo-inductive)
Guided tissue regeneration - membrane placed between epithelium and underlying tissues to stop the down-growth of epithelium and allow slower-growing bone/CT to mature/grow into the defect. Resorbable.
Growth factors and organic materials e.g. Enamel matrix proteins applied directly onto root surface =
forms amelogenin and stimulates alveolar bone formation, cementoblasts, PDL, collagen = reduces attachment loss
Guided tissue regeneration
Guided tissue regeneration - membrane placed between epithelium and underlying tissues to stop the down-growth of epithelium and allow slower-growing bone/CT to mature/grow into the defect. Resorbable.
GTR - growth factors and biological additives
Growth factors and organic materials e.g. Enamel matrix proteins applied directly onto root surface =
forms amelogenin and stimulates alveolar bone formation and reduces attachment loss
Treatment of peri-implantitis
- Flap
- Debride area
- Bio-oss and resorbable membrane
- Close and suture flap
- OHE, reviews
What is gingival recession
Gingiva moving away from CEJ
Exposing the root surface
Aetiology of gingival recession
Inherited or acquired factors + precipitating factors
Factors affecting the presence and extent of gingival recession [6]
Periodontal phenotype Trauma Tooth position Periodontal disease and treatment - Inflammation, PMPR, bone loss Muscle attachments - Can make it harder to keep areas clean - Force applied to the gingiva Iatrogenic - RCT irrigants, clamps, heat from US, surgery
How does periodontal phenotype affect gingival recession
Bucco-lingual bone thickness
- Bone morphology/bone thickness
Gingival phenotype
- Gingival thickness (check by putting a probe in the sulcus and seeing how much it shows)
- Keratinised tissue width (from the gingival margin to mucogingival margin)
Trauma affecting gingival recession
Mechanical - Aggressive tooth brushing Chemical - Smoking, burns, drugs Physical - piercings, badly designed dentures
Tooth position affecting gingival recession
Buccally placed tooth means thinner bone and gingiva here
- Dehiscence = no alveolar bone at the coronal margin
- Fenestration = area of no alveolar bone
Class 2 Div 1 or 2 (retroclined) - if deep overbite
- Trauma to palatal gingiva of upper incisors
- Trauma to labial gingiva of lower incisors
- Trauma to palatal surface of upper incisors and labial surface of lower incisors
Consequences of gingival recession
Aesthetics
Sensitivity
Root caries or non-carious lesions
How to diagnose gingival recession
Clinical and rad assessment
- Gingival thickness and keratinised tissue width
- Bone levels and thickness
- Interproximal attachment loss
Miller’s classification of gingival recession
1 = Recession not extending to CEJ and no interproximal attachment loss 2 = Recession extending to or beyond CEJ and no interproximal attachment loss 3 = Recession extending to or beyond CEJ and interproximal attachment loss/soft tissue/abnormal tooth positioning 4 = Recession extending to or beyond CEJ and severe interproximal attachment loss/soft tissue/severe abnormal tooth positioning
1 and 2 full root coverage expected
3 partial root coverage expected
4 no root coverage expected
Cairo et al., classification of gingival recession
1 = buccal recession defect with no interproximal attachment loss 2 = buccal recession defect is greater than the interproximal attachment loss 3 = interproximal attachment loss is greater or equal to the buccal recession defect
1 Full root coverage expected
2 partial root coverage expected
3 no root coverage expected
Histological theory/classification of gingival recession
Proliferation of the epithelium into CT and reduction of CT layer until eventually epithelium proliferation merges and loss of CT = recession
Conservative/initial management of gingival recession
Baseline measurements
- Photos
- Models
- Measurements - indices, recession, full perio
OHE, stabilise any periodontal disease
Sensitivity management - fluoride varnish, desensitising agent, restorations
Non-surgical management options for localised recession defects
Pink composites
Pink ceramics for crowns
Gingival veneer (soft or hard acrylic, but stains and is plaque retentive)
Surgical management options for localised recession defects
Coronally advanced flap
Free gingival graft (from donor site e.g. palate)
Laterally advanced flap
- flaps all need to be keratinised tissue
+/- Growth factors, GTR, CT graft
Multiple donor sites = less good
Some flaps e.g. coronally and lateral advance only cover 1 or 2 teeth, but only 1 surgical site, no interrupted blood supply and are easy to do
CT graft is good for large defects or lots of bone loss - taken from a palatal donor site (envelope technique), and used under a coronally or laterally repositioned flap
Indications for surgical management of localised recession defects
Aesthetics
Sensitivity
Progressive recession or attachment loss
Recession beyond the CEJ
Pre-op assessment before surgical recession management
Photos, baseline assessment
Informed consent - Alternative treatment, risks, benefits explained
MH, SH
Measurements
Clinical exam
- Vitality testing of teeth
- Bone levels - need good levels for success
- Gingival thickness, keratinised tissue width
- Interproximal attachment - need good levels for success
Is the recession or perio active or stable
General steps for surgical recession management
- Flap e.g. Coronally advanced flap
- Root surface conditioning – remove granulation tissue, calculus, etc.
- CT graft/GTR/growth factors like emdogain/enamel matrix derivative applied
- Suture
- Periodontal dressing
- Maintenance care
Tooth restoration cycle [6]
Initial lesion and restoration
- Structural degradation + increased stress (fatigue, changed physical properties, adjacent restorations) =
- restoration failure
- Replacement restoration
- = further loss of tooth structure
- Occlusal loading, reduced support, parafunction, etc. = structural degradation and back to start of cycle
Amalgam vs composite - reasons for failure
Amalgam = tooth fracture
Composite = restoration fracture
And in high caries risk patients, composite’s don’t do well.
But in low caries risk patients, composites last longer.
Survival of restorations depends on [3]
Placement and handling technique and quality
Maintenance
Environment
Consequences of polymerisation shrinkage [6]
Marginal leakage Staining at margin Post-op sensitivity Micro-fractures in enamel Debonding Secondary caries
C-factor
Amount of strain put onto the walls of the tooth - calculated by ratio of bonded surfaces : free surfaces, so bigger C-factor is worse.
How to reduce polymerisation shrinkage in composites [2]
Flowable composites/more filler
Better technique e.g. increments
Amalgam pros and cons
Advantages
- Durable
- Cost effective
- High tensile strength
- Easy placement - doesn’t need moisture control
- No polymerisation shrinkage
Disadvantages
- Not aesthetic and causes staining
- Need to prepare he tooth = loss of tooth structure
- Corrosion
- Mercury - sustainability, environmental and health impacts of disposal
- weakens tooth bc no bonding = fractured tooth
Erosive tooth wear - aetiology and about it
1/3 of people have it
If in primary teeth, it can increase the risk of having it in permanent teeth
Caused by erosion + attrition + abrasion
Erosion can be due to intrinsic (GORD/eating disorder) or extrinsic (diet)
Patients can have excellent plaque control
Signs of erosive tooth wear
Buccal lesions
Enamel has cracks and is thinner or weaker
Loss of enamel
Upper incisors and first molars are the most common sites
Screening questions to ask patient about erosive tooth wear
Diet
- Acidic drinks - how often, when do you have them, how do you drink them e.g., swirl around the mouth, hold it in mouth, straw
- Acidic snacks/fruits - when and how often
Brushing habits and toothpaste
GORD/eating disorder
Medications (acidic, sugary, dry mouth)
Xerostomia
BEWE
Basic erosive wear exam
A screening tool, to be used when you’re doing an exam and BPE. Score each sextant on the worst site within that sextant.
0 = no erosive wear 1 = loss of surface enamel texture 2 = clear lesions, hard tissue loss e.g. dentine, <50% 3 = hard tissue loss e.g. dentine, >50%
And then add up the scores for all the sextants 0-2 = - repeat at the next exam 3-8 = - repeat at the next exam - OHE, diet advice, low abrasion toothpaste 9-13 = - as above - repeat every 6-12 months - no restorations - find the aetiology of their TSL and manage - Consider fluoride varnish - monitor w study casts, photos, etc. 14+ = - as above - restorative interventions - referral
Management/Tx of Erosive tooth wear
Stop it getting worse
- Find cause
- OHE/brushing
- Diet
- Manage extrinsic factors causing erosion
Re-mineralise/protect the enamel
- Fluoride varnish
- Toothpaste
- MW
- Restorations
Manage any sensitivity and aesthetic concerns of patient
Monitor using images, models
Advice to give patients about erosive tooth wear
Diet
- Limit the frequency of acidic food and drinks and have them at mealtimes (try not to have acidic drinks every day)
- Don’t brush immediately after an acid attack or vom
- MW, water or milk afterwards
- Straw
Brushing
- Non-aggressive technique
- Non-abrasive toothpaste e.g. Proenamel
- Soft toothbrush
Extrinsic - See a doctor about GORD/eating disorders
Management of patients complaining of dentine hypersensitivity
- Pain history - short sharp pain w stimulus
- Exam
- Exclude other diagnoses
- First-line treatment = desensitising toothpaste
- Review and if symptoms haven’t improved - try different treatment
- Regular reviews
How to diagnose dentine hypersensitivity
Rule out differentials:
- PA periodontitis
- Pulpitis
- Pericoronitis
- Cracked tooth syndrome
- Post-op sensitivity
Exam
- Good lighting, dry teeth
- TTP, sensibility testing
- Stimulus tests e.g. cold air
- PA
How to treat dentine hypersensitivity
Prevention
- diet
- brushing
- reduce risk factors
Cover tubules
- restorations
- varnish
- desensitising agent
- sensitive toothpaste
Aetiology and definition of dentine hypersensitivity
A short sharp pain due to exposed dentine in response to a stimulus that isn’t caused by any other dental defect or pathology
Caused by recession or tooth wear - exposed dentine = exposed tubules and a stimulus causes fluid movement and excites the pulp nerves = pain
Who is at risk of getting dentine hypersensitivity
Anyone at risk of TSL - erosive, bruxism, parafunction, aggressive brushing
Xerostomia
Periodontal disease
Different toothpaste technologies for treating dentine hypersensitivity
Novamin (in Sensodyne)
Stannous Fluoride (and reduces plaque formation at gums)
Arginine
- all create a robust layer on top of or inside the exposed tubules (i.e. blocks them)
Potassium nitrate
- desensitise the nerves by depolarising them
All need to be used long-term
Considerations before planning on filling gaps (partially edentulous patient)
- Structural integrity and durability
- Reduced if RCT or post and core - Restorability
- Unrestored coronal dentine - Retention and resistance for crowns/bridges
- Ferrule 2-3mm
- Guidance contacts? - Periodontal health and support
- OH/compliance
- Bone levels (if low, root can fracture)
- Abutment teeth more susceptible to perio - Patient suitable for implants?
- Informed consent, risks, costs, complications - Cleansability and maintenance
- RPD is less cleansable
- Implants can get implantitis/mucositis if not maintained - Risk factors
Gold standard periodontal surgery type
Coronally advancing pedicle flap + CT graft
= same colour, dual blood supply, smaller wound on palate/donor site, can be used for multiple sites
Coe pack
Post periodontal treatment e.g. on the donor or recipient site
Resin-based cements for indirect restorations
Strongest because strongest bond to the tooth
High compressive strength
But have more stages/are more complicated and are expensive to use - need etch and bond like w composite.
Light cure e.g. Rely X Veneer. Less strong but more colour stable
Chemical Cure e.g. RelyX Unicem (self-adhesive so doesn’t need separate etch or bond but less strong bond)
Dual cure e.g. RelyX ultimate
