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Transcript of The brilliant Formula 1904 - bsdht.org.uk Robb LA Handout.pdf · Self‐aspirating mechanism (Astra...
1
Local anaesthesia for the 21st
Century – an update
BSDHT Liverpool ACC 10th November 2012
Dr Nigel D RobbReader in Restorative
Dentistry
Traditional local anaesthetics
• Lidocaine • Prilocaine• Mepivacaine
New Local Anaesthetics and Equipment
• Articaine• Phentolamine
mesylate(OraVerse)
• Computer controlled delivery systems
( )• Oraqix
Importance of local anaesthesia in dentistry
The severe pain caused by diseases of teeth and jaw is a sign of the importance of
these parts of the body.
Local anaesthesia is an invaluable good for a
dentist. It is his commitment to have a very good command of it in all
scientific and technical aspects.
Guido Fischer 1911
Use of vasoconstrictors
I read about the possibility to produce an extract of the adrenal gland of animals which constricts
blood vessels.
A few days later I got a small amount of this extract, mixed it up with cocaine and injected it
into my forearm.
Immediately I knew that this was the dawn of a new period of
local anaesthesia.Heinrich Braun 1900
concentration 1: 600.000
The brilliant Formula The brilliant Formula 1904 1904
++ ++ ==Local
Anaesthesia
Drug DeliverySystem
Technique Outcome++ ++ ==
2
Choice of local anaesthetic agent
• Lidocaine (2%) and epinephrine (1:80 000)– Gold standard in UK
Active in 2 3 mins (infiltration)– Active in 2-3 mins (infiltration)
– Duration 45-60 mins
– Max dose 4.4mg/kg up to 300mg maximum
Role of lidocaine
• First choice local anaesthetic in UK clinical practice
• Currently routine choice
Prilocaine 3% + 0.03 IU felypression
• 2.2ml cartridges• 30mg prilocaine and 0.54g felypressin / ml• Maximum safe dose
of prilocaine 6mg/kg up to maximum ofof prilocaine 6mg/kg up to maximum of 400mg
• 1/10th rule does not apply maximum 6 cartridges
Role of prilocaine and felypressin
• Use when epinephrine best avoided– Allergy to reducing agent
– Acute coronary syndromes• Unstable angina• Unstable angina
• Refractory arrythmias
– Concurrent use of cocaine or other illicit stimulants
Felypressin and ischaemic heart disease
• Can cause coronary artery constriction
• Limit dose to 3 cartridges in patients with ischaemic heart diseasewith ischaemic heart disease
Mepivacaine 3% or 2% +1:100 000 epinephrine
• 2.2ml cartridges• 30mg or 20mg mepivacaine and
10g epinephrine per mlM d 4 4 /k t i• Max dose 4.4mg/kg up to maximum of 300mg
• 1/10th rule for 2% not for 3% - up to 6.8 cartridges for 2%, but only 4.5 cartridges for 3%
3
Role of mepivacaine
• Use plain solution when epinephrine contraindicated– Better for blocks than infiltrations
2% with epinephrine comparable• 2% with epinephrine comparable with lidocaine, but slightly shorter duration of action
Articaine HCL
1974
Choice of local anaesthetic agent
• Articaine (4%) with adrenaline epinephrine (1:100 000 or 1:200 000)
Advantages of short half life (30mins)– Advantages of short half life (30mins)
– Use serially toxicity less likely
– Now emerging evidence of improved efficacy / diffusing power etc
– Maximum dose 7mg/kg
Articaine
• Marketed for improved diffusing properties
• Makes IAN Blocks obsolete“ h i t t ti d• “…… has intense penetrating and spreading powers. Infiltration is possible in the mandible eliminating the need for mandibular block.”
Articaine
“Xylocaine has intense penetrating and spreading powers. Infiltration is possible in the mandible eliminating the need for mandibular block.”Bremer et al, 1948
Difficult to demonstrate
Recent studies show articaine more effective in buccal infiltration next to molars and upper lateral incisors
Articaine
• This review supports the argument that articaine compared with lidocaine provides a higher rate of success with comparable safety tosuccess with comparable safety to lidocaine when used for infiltrations or blocks
• Causes slightly more post injection pain
4
Articaine
• Rcommendation that 4% articaine (+ 1:100 000 epinephrine) to replace lidocaine (+ 1:100 000 epinephrine)
Non surgical paraesthesias???
• “Thus there is an urgent need for further studies focused on the neurotoxicity of local anaesthetics with specific focus on articaine 4%with specific focus on articaine 4%. Until factual information is available, a preference for other formulations to 4% articaine may be justified, especially for mandibular block anaesthesia.”– Hillerup and Jensen, 2006
Non surgical paraesthesias???
• “Regarding articaine, the conclusion is the safety profile of the drug has not changed since its launch (1998). Thus no medical evidence exists toThus, no medical evidence exists to prohibit the use of articaine…”– Pharmacovigilance Working Party of
EU, 2006
Non surgical paraesthesias???
• Study of 53 patients (1/1/2003-31/12/2005– Symptoms 9/12 after injection– 35% lidocaine– 30% articaine– 30% prilocaine
• On the figures….we do not see a disproportionate involvement from articaine– Pogrel, 2007. Danish Medicines
Agency, 2008
Non surgical paraesthesias???
• Study of referrals in Denmark appears to implicate articaine– Some bias – non returning patients
classified as “potentially permanentclassified as potentially permanent damage”
– Fall in referrals after 2005 no real reason given
– Doesn’t quote Pogrel 2007
Practical advice
• There is no restriction on use of articaine for inferior alveolar nerve blocks
• In UK defence organisations will• In UK defence organisations will support you if you use it
• In UK defence organisations will support you if you don’t use it
5
Plasma concentration of tritium labeled epinephrine after intra oral injections in
volunteers
20 % partial
Regional Anaesthesia
1994
intra vasal injections
Up to 80 fold increase of epinephrine
levels
70.000.000 administrations/year• 90 % Articaine 4 %:
– Epinephrine 1:100.000 (~ 45 %)– Epinephrine 1:200.000 (~ 55 %)
Local Anaesthesia in Germany
6,1
3,1
0
1
2
3
4
5
6
7
Articaine 200 ( n = 664 ) Articaine 100 ( n = 547 )
%
p p ( )
• Side effects: 4,5 %
Anesth Prog, 1997 p = 0,0411
Aspiration
A vital step when injecting dental anaesthetic
Why?
• Deposition of any anaesthetic into a blood vessel can result in systemic disturbances.
• Deposition of any anaesthetic into a blood vessel causes the solution to dissipates around the body; anaesthesia reduced
Aspiration technique
Basic principle:To create a negative pressure in the cartridge ‐ liquid from the tissue at the deposition site is sucked upBefore injecting :1. Insert the needle
2. Aspirate by pulling plunger back, check for blood in
Standard Self-Aspirating
cartridge, if so reposition the needle and try again. DON’T INJECT UNLESS NEGATIVE!
Aspiration can be performed actively or passively with standard cartridges or passively with self‐aspirating cartridges.
Manual
Manual Aspiration ‐ Standard Cartridges
Standard dental cartridges have a solid bung ‐pierced by a barb or hook on the syringe plunger.
Aspiration by manually pulling back the plunger to create negative pressure
DISADVANTAGE: Risk of the needle moving during aspiration ‐ risk of false negative
Passive Aspiration System ‐DENTSPLY Self‐Aspirating Cartridges
Mechanism of the DENTSPLY Self‐Aspirating Cartridges (Astra type)
• Self – aspirating is a more reliable than manual aspiration• No active movement from operator required
• Self‐aspiration cartridges have specially adapted bung, needing different syringe plunger
• Thin centre of the bung distended when pressure exerted.
• When force stopped the bung returns to usual shape ‐negative pressure (aspiration)
6
Self‐aspirating mechanism (Astra type)
21
43
1
Other aspirating systems
Phentolamine mesylate (OraVerse)
• Nonselective -adrenergic blocking drug
• First therapeutic agent for reversal of soft tissue anaesthesiasoft-tissue anaesthesia
• Median lip recovery times reduced by 75 - 85 minutes
• Clinical use viewed favourably by dentists and patients
• No serious adverse events reported
Percentage of patients reporting normal sensation 30 mins post PM
injection
Arch PM ShamMax 26.7 1.7Mand 17.2 0.8
Tavares et al, J Am Dent Assoc 2008
Phentolamine mesylate (OraVerse)
• Costs $10-12 (£6.20 – 7.40) per 1.7ml cartridge
• Prohibitive for routine use at present
1853 1904 1999 130 years1897
The delivery systemsThe delivery systems
7
Application of new technologyApplication of new technology
The Wand - 1997The Wand - 1997 CC Syringe - 2001CC Syringe - 2001
The WANDThe WAND
Disposable handpiece
Microprocessor
Foot control
Precision needle control pen grip
Speed of Delivery
Flow Rate?Flow Rate?
• Direct positive correlation between pressure and pain exists in dentistry.
• Pressure direct positive correlation with flow-rate.
Clinical Relevance
• To decrease pain and anxiety of local anesthetic injection use pressure less then 306 mmHg (6 psi) in movable mucosa.
A Correlation exists:
“Tissue Type” and “Exit-pressure”
8
Pulpal
Palatal
Labial/Buccal
AMSA AMSA -- anaesthetized anaesthetized areaarea
Williams WP (1999)Williams WP (1999)Williams WP (1999)Williams WP (1999)
Single injection for multiple teeth
Crosses midline
Single injection for multiple teeth
Crosses midline
PP--ASA ASA -- advantagesadvantages
Reduced dosage of anaesthetic
No unwanted soft tissue anaesthesia
Reduced dosage of anaesthetic
No unwanted soft tissue anaesthesia
Pulpal
Palatal
Labial
PP--ASAASA -- anaesthetised areaanaesthetised area
*7
Petzer (2001)
STA - SystemSingle Tooth Anesthesia
9
The Formula 2008The Formula 2008
++ ++ ==Local
Anaesthesia
Drug DeliverySystem
Anatomy Outcome++ ++ ==
“Innovation Defines Our Future”“Innovation Defines Our Future”
====Local
Anaesthesia++++ ++++
What is Oraqix®?
• Oraqix® 25/25 mg per g Periodontal Gel (2.5% lidocaine, 2.5% prilocaine)
• Same active ingredients as EMLA®
– 2.5% lidocaine; 2.5% prilocaine
• Anaesthetic drugs in Xylocaine® and Citanest®• Anaesthetic drugs in Xylocaine and Citanest , respectively
– White cream for skin anaesthesia
• Pre canulation
– Not licensed for dental use
What is Oraqix®?
• Oraqix®
– Contained in a clear liquid
– Still 2.5% lidocaine; 2.5% prilocaine
A liquid that sets as a gel at body– A liquid that sets as a gel at body temperature
– Oraqix® is a POM (Prescription Only Medicine)
Oraqix®
• Licensed indications– Oraqix® is a non-injectable dental local
anaesthetic indicated in adults for localised anaesthesia in periodontal ppockets for diagnostic and treatment procedures such as probing, scaling and/or root planing
How do we use it?
10
What is in the box?
• Supplied in 1.7g Glass cartridges– Box of 20 cartridges
– Each cartridge is supplied with a blunt tip applicator
• Each cartridge– 42.5mg lidocaine
– 42.5mg prilocaine
Cartridges
• The air-bubble is larger than in injectable local anaesthetics, and does not pose a risk as Oraqix® is not injected
Cartridges
• Oraqix® should be a liquid when administered. If it has gelled, cool until becomes a liquid again. Visible air bubble moves when tilting cartridge
Cartidges
• Not labelled “sterile”• Manufactured
aseptically, like injectable anaesthetics– Cartridge can be
disinfected with 60% ethanol or 60-70% isopropanol wipes
Unassembled Dispenser Inserting Cartridge
11
Bending Applicator Tip
• Can be bent to aid access• Bend using tip cover• Do not bend at hubDo not bend at hub
Ready for use
Application
• Depress paddle to dispense liquid
ApplicationApplication
Position of tip of applicator
• Applicator tip in gingival crevice / periodontal pocket
• Inject and move jround tooth
Timings
• Effective in 30 seconds,
• Duration 20 minutes– Sufficient in one
cartridge to ca t dge toanaesthetise one quadrant
– Can be site specific • Apply to two or three
sites at a time
12
Maximum dose
• Maximum dose is 5 cartridges in one treatment session
• Maximum dose cumulative if usedcumulative if used with injectable local anaesthetics
Scaling Showing RemovalScaling Showing Removal
Clinical Studies: Safety
• 10 patients– At least 16 teeth with pockets 4mm
– Application of Oraqix® to all teeth (18-28) 0.9-3.5g
– SRP on 3 teeth.
• Maximum plasma levels detected 20 40 min after• Maximum plasma levels detected 20-40 min after application– Lidocaine (99-266 ng/ml)
– Prilocaine (46-118 ng/ml)
• Initial signs of CNS-toxicity at 5000 ng/ml• Plasma levels of lidocaine and prilocaine after application of
Oraqix®, a new intrapocket anesthetic, in patients with advanced periodontitis
Friskopp J & Huledal G, J Clin Periodontol 2001
Clinical Studies: Duration and Onset
• 30 patients
– Oraqix® applied and left for 30 seconds, 2 minutes and 5 minutes
– SRP on 2-3 teeth
• Pain assessment with Visual Analogue Scale (VAS; 100mm)Pain assessment with Visual Analogue Scale (VAS; 100mm) and Verbal Rating Scale (VRS; 5 levels)
• Duration of anaesthesia probing using “normal force” 5 minutes intervals until sensation returned or 30 minutes after end of SRP
• Evaluation of side effects by follow-up phone call 24-48 hours after SRP
The anesthetic onset and duration of a new lidocaine/prilocain gel intra‐pocket anesthetic (Oraqix®) for periodontal scaling/root planing. Friskopp J et al., J Clin Periodontol 2001
Clinical Studies: Duration and Onset Results
• Visula Analogue ScaleTime VAS (median) Duration (mean)30 sec 7.5 mm 18.1 minutes2 min 28.5 mm 17.3 minutes5 min 15.5 mm 19.9 minutes
• VRS– no patient severe or very severe pain– no significant differences between groups
• Conclusion
– Oraqix® provides anaesthesia after 30 seconds
– Duration of action 17-20 minutes
Clinical Studies: Efficacy
• 122 patients at 8 centres Oraqix® or placebo - 30 seconds - 2 minutes, SRP on one quadrant.
• Patient discomfort
– second application of gel
• Discomfort continuedDiscomfort continued
– classed as in need of a rescue anaesthesia (Injection)
• Measurements– Pain assessment Visual Analogue Scale (VAS; 100mm) and
Verbal Rating Scale (VRS; 5 levels)
– Need of a rescue anaesthesia
Intrapocket Anesthesia for Scaling and Root Planing: Results of a Double‐Blind Multicenter Trial Using Lidocain Prilocaine Dental Gel
Jeffcoat MK et al., J Periodontol 2001
13
Clinical Studies: Efficacy Results
• VAS– Oraqix®: 7 mm
– Placebo: 17 mm (median)
– VAS significant reduction in reported pain. Mean reduction 8mm compared to placebogroup (p < 0.0005, Hodges-Lehmann estimate)
• VRS– Oraqix®: 90% of patients no pain or mild pain– Placebo: 64% of patients no pain or mild pain
Clinical Studies: Efficacy Results
• Rescue anaesthesia– Oraqix®: 11% of patients (7 of 63)– Placebo: 17% of patients (10 of 59)– Trend noted: higher efficacy in deeper pockets
with more pronounced inflammationwith more pronounced inflammation
Clinical Studies: Efficacy in “Pain Sensitive
Patients”• 85 patients at 4 centres, VAS scores on probing greater
than 30, Oraqix® or placebo for 30-45 seconds, SRP on one quadrant
• If the patient had any discomfort– second application of gel
• If discomfort continued– classed as in need of a rescue anaesthesia (Injection)
• Measurements– Pain assessment with VAS 100 mm
– Pain assessment with VRS (5 levels)
– Need of a rescue anaesthesia
Intrapocket Anesthesia for Scaling and Root Planing in Pain‐Sensitive Patients
Magnusson I et al., J Periodontol 2003
Clinical Studies: Efficacy in “Pain Sensitive Patients” Results
• VAS– Oraqix®: 11 mm
– Placebo: 27 mm
– The VAS significant reduction in reported pain. Mean reduction of 10 mm vs placebo-group (p < 0.004, Hodges-Lehmann estimate)
– Results similar between centres
• VRS (p=0.003)– Oraqix®: 70% of the patients reported no pain or mild
pain– Placebo: 48% of the patients reported no pain or mild
pain
Clinical Studies: Efficacy in “Pain Sensitive Patients” Results
• Rescue anaesthesia– Oraqix®: 5% of the patients (2 of 43)– Placebo: 17% of the patients (7 of 42)– Trend noted: higher efficacy in deeper pockets with more
pronounced inflammation
Clinical Studies: Oraqix® vs Infiltration
Anaesthesia• 175 patients, 8 centres
– Oraqix® vs. Xylocaine® 2% with Adrenaline
• Two treatment visits one week apart – 2 quadrants one side Oraqix®q q
– 2 quadrants other side injection
• Apple Newton® Message Pad for evaluation by the patients
Patient evaluation of a novel non‐injectable anesthetic gel – a multicenter crossover study comparing the gel with infiltration anesthesia during scaling and root planing van Steenberge D et al., J Periodontol 2004
14
Clinical Studies: Oraqix® vs Infiltration Anaesthesia Results
Gel (n=157) Injection (n=157)
Satisfactory anaesthesia duringSRP?
(patient opinion)
Gel (n=157) Injection (n=157)
Very satisfactory 34% 51%
Satisfactory 45% 45%
Not completelysatisfactory
17% 4%
Unsatisfactory 3% 0
Preference of patients70 % (110 of 157) patients preferred Oraqix®
22 % (35 of 157) patients preferred the injection8 % (12 of 157) patients had no preference
Clinical Studies: Oraqix® vs Infiltration Anaesthesia Results
Gel (n=110) Injection (n=35)
Reason for Patient Preference
Less pain 19 80
Less discomfortafterwards
22 23
Less numbness 70
Absence of injection 35
Less apprehension re feeling pain
- 11
Clinical Studies: Oraqix® vs Infiltration Anaesthesia Results
Gel injection
Ability to perform adequate treatment (investigator’s opinion)
Very satisfactory 42% 83%
Satisfactory 34% 17%
Not completely satisfactory
20% 0
Unsatisfactory 4% 0
Review of Findings
• Flexible use– Local, quadrant, arch,
• Safe in clinical use• Rapid onset (30 seconds) • Acceptable duration ~20 minutes• Can be reapplied
Review of Findings
• Good pain elimination• Good patient comfort
– No injection
N t ti ft ti– No post operative soft tissue anaesthesia
• 70% of the patients preferred Oraqix® to conventional anaesthesia
• Improved compliance with SRP treatments
Summary
• Treat local with respect• Reflective practice• Patients appreciate efficacy
– Dislike postoperative numbness and injections
• Use LA appropriately and effectively
15
Thank you for your kind attention