Current Use of Antimicrobials Flashcards
G O A L S O F _______ T H E R A P Y
Arrest the disease
Alter the microflora to prevent reinfection
Maintain the disease in an arrested state
Antimicrobial
An effective \_\_\_\_\_ does the following things: • kills or inhibits target microflora • reaches the site • has an adequate concentration • has a sufficient duration • does not harm
Antimicrobial
Crevicular concentration is high using ______ delivery with a very
small dose of antimicrobial
Local delivery
T/F; Antimicrobial agents are never used in the absence of mechanical
debridement
True
Is it effective to give ABX to a perio pt without mechanically debriding?
Not effective: Debride then prescribe
I N D I C A T I O N S F O R _______
Applications :
✓Localized & Generalized aggressive periodontitis (old classification) / Grade C
✓Necrotizing gingivitis and periodontitis
✓Periodontitis associated with or aggravated by systemic disease (e.g. poorly
controlled diabetes)
✓Diffuse periodontal abscess with fever, malaise, etc
✓Patients in whom periodontal surgery is contraindicated
A D J U N C T I V E
A N T I M I C R O B I A L T H E R A P I E S D U R I N G
P H A S E I ( N O N - S U R G I C A L ) T R E A T M E N T
(ABX prescription with phase 1 debridement)
: the most studied and most effective rinsing
agent for plaque inhibition and prevention of gingivitis
No systemic toxicity, rare hypersensitivity
Active against most bacteria and fungi
No microbial resistance reported
Taste and tooth discoloration side effects
Cannot reach the site subgingivally
Chlorhexidine gluconate (CHX) (0.12-0.2%)
Extrinsic _______ of the teeth of an individual rinsing
twice a day for 3 weeks with a 0.2% chlorhexidine mouth rinse
(Europe), can be alleviated with 0.12% formulation (US).
Beverages like tea, coffee and red wine will aggravate this
superficial staining. Can be removed using prophy paste.
brown discoloration
Which conc of CHX can be used to decrease the amount of extrinsic staining? Can the stains be removed with prophy paste?
.12%; Can be removed with prophy paste
_____ mechanism of action
Cationic, binds to negatively charged bacterial cell membranes
that, at lower concentrations leads to increased permeability and leakage, at higher
concentrations this membrane leakage leads to cytoplasmic entry and precipitation
of cytoplasmic contents inducing microbial cell death.
Cationic nature contributes to high substantivity once it binds to salivary pellicle: slow
release from tooth surfaces over 12 hours!
CHX MOA
W H E N D O W E
P R E S C R I B E ______?
• As adjunct to regular oral hygiene methods during Phase I therapy (SRP)
only in high risk individuals (systemically compromised, refractory
cases, etc)
• Mentally or physically challenged patients with low manual dexterity
• Jaw fixation
• 1st - 2nd week post surgery
C H X
R I N S E ?
Studies have shown conflicting results
1.5% effective as rinse (Boyd, 89)
oral ulcerations with 3% rinse (Rees, 86)
3% and 30% used as twice weekly rinse had issues
long term use can lead to pre-neoplastic lesions (Weitzman, 86)
ADA and FDA have concerns regarding long term use
possible co-carcinogen and impaired wound healing
Hydrogen peroxide
reaches the site with a sufficient concentration has a poor duration of action
Antimicrobial irrigation
What 2 things are used in antimicrobial irrigation?
CHX .12%
Betadine
kills the pathogens effectively reaches the site very well has a very good concentration has a very good duration of action Ideal properties: effective against periodontal pathogens low systemic absorption low risk of bacterial resistance biodegradable easily to use enhances scaling and root planing
Local delivery of antimicrbials
Systemic or local drug delivery? Site specific therapy Better control of concentration, local effective dose Limited or no systemic adverse effects In office delivery, ensures compliance
Local delivery
: 10% povidone-iodine and 1% free iodine and can be used diluted as an irrigant.
do not use if any history of iodine sensitivity
use with caution in pregnancy and lactation because of the possibility of inducing
transient hypothyroidism in newborns
Betadine®
What is the most popular direct delivery antimicrobial?
Arestin
______ is (minocycline hydrochloride) in microspheres
(bioresorbable polymer of Poly(glycolide-co-dl-lactide)
or PGLA
available in 1 mg unit doses of dry powder
bacteriostatic, broad spectrum, inhibits protein synthesis
Arestin®
When do we use _______?
Always as adjunct to SRP, never stand alone therapy
Residual isolated pockets ≥5mm, not responding favorably to
initial SRP, especially if BOP is present at re-evaluation.
Residual pockets after phase II (periodontal surgery)
Used at time of reevaluation
Used during maintenance
Used to treat a periodontal abscess
Used before regenerative therapy
local antimicrobial
drug delivery
Is local drug delivery effective around implants?
Not effective
T/F: T H E “ I D E A L ” A N T I B I O T I C F O R P E R I O D O N T I T I S
D O E S N O T E X I S T
True
Broad spectrum bacteriostatic High concentration in GCF (2-10 fold>serum). Highly e f f e c t i v e a g a i n s t A . actinomycetemcomitans, but re s i s t a n t s t r a i n s a re n o w c o m m o n . I n a d d i t i o n t o antimicrobial they also have anti-collagenolytic effects: i n h i b i t c o n n e c t i v e t i s s u e d e s t r u c t i o n a n d p ro m o t e repair Photosensitivity: severe skin burns
Tetracyclines
Broad spectrum bactericidal Used in combination with metronidazole Up to 10% of humans are allergic to penicillins (can substitute with ciprofloxacin, clindamycin or erythromycin)
Penicillins
(Amoxicillin and
Augmentin)
Particularly effective against anaerobic b a c t e r i a a n d spirochetes, bactericidal Never used as monotherapy in periodontal diseases but a s c o m b i n a t i o n w i t h penicillins or ciprofloxacin Adverse reaction (nausea, vomiting, cramping) when taken with alcohol. Not to be combined with anticoagulants or lithium
Metronidazole
Compliance is better with DCN
because it can be given qd or bid,
but photosensitivity is a problem
C o m m o n l y p re s c r i b e d i s a l s o
metronidazole in combination with
amoxicillin or cipro.
Clinical results of systemic therapy
are similar to local delivery
Doxycycline (DCN)
Target prostaglandins and inflammation Selective COX-1 vs COX-2 inhibitors E.g: Indomethacin, flurbiprofen and naproxen long term daily use (up to 3 years) can lead to slower disease progression Serious side effects (renal, hepatic, GI tract). They are not used as adjuncts in periodontal therapy
NSAIDs
Disrupt osteoclast activity
Can improve alveolar bone density but
their role in disease progression in humans
is unclear
Serious side effects with IV agents
(osteonecrosis of the jaw after oral surgery)
There is currently no approved application
in periodontal therapy
Bisphosphonates
Of most tetracyclines ______ has best anti-
collagenolytic activity and better GI absorption
Doxycycline (DCN)
• Monochromatic light
• Consists of a single wavelength of light and three principal parts:
-an energy source,
-an active lasing medium
-two or more mirrors that form an optical cavity or resonator
• The wavelength and other properties are determined primarily by the composition
of an active medium (it can be a gas, a crystal, or a solid-state semiconductor)
4 different interactions with a target tissue:
Reflection
Transmission
Scattering
Absorption
Lasers
How do most lasers interact with target tissue?
Absorption
When absorbed, it elevates the temperature and produces photochemical effects depending on
the water content of the tissues.
When a temperature of 100°C is reached, vaporization of the water within the tissue occurs
(ablation)
At temperatures below 100°C, but above approximately 60°C, proteins begin to denature,
without vaporization of the underlying tissue.
Conversely, at temperatures above 200°C, the tissue is dehydrated and then burned, resulting in
an undesirable effect called carbonization.
Absorption requires an absorber of light, termed chromophores, which have a certain affinity
for specific wavelengths of light.
The primary chromophores in the intraoral soft tissue are Melanin, Hemoglobin, and
Water, and in dental hard tissues, Water and Hydroxyapatite.
Different laser wavelengths have different absorption coefficients with respect to these
primary tissue components, making the laser selection procedure-dependent
Absorption of lasers
___ lasers
• Used soft tissue treatments
• Despite their bactericidal efficacy, they are not effective for calculus removal
• May be helpful as an adjunct to SRP due to having bactericidal and detoxing
effects.5
• Low-level laser has also been recommended for pain reduction and enhancing
wound healing due to its anti-inflammatory effects.
- Basic, cheapest
- Hemoglobin and melanin used as chromophores: not used on hard tissue
Diode lasers
____ lasers
• PDT (Photodynamic Therapy): Low-level laser irradiation in conjunction with the use
of a photosensitizer modality of bacterial reduction
• Free Radicals
PDT & NON- PDT
____ lasers
Highly absorbed by the pigmented tissue
Effective surgical laser for cutting and coagulating dental soft tissues
Good hemostasis. In addition to its surgical applications
Used for nonsurgical sulcular debridement in periodontal disease control and the Laser Assisted
New Attachment Procedure (LANAP).
Nd:YAG lasers
______ lasers
The erbium wavelengths have a high affinity for hydroxyapatite
highest absorption of water in any dental laser wavelengths
laser of choice for treatment of dental hard tissues
Can also be used for soft tissue ablation ( because they contains a high percentage of
water)
Erbium lasers
When do we prescribe prophylactic antimicrobials?
Sub actue bacterial endocarditis
The following are indications for ______:
‣Prosthetic cardiac valves, including bio-prosthetic and homograft valves (from
a cadaver)
‣Previous bacterial endocarditis
‣Congenital heart disease
‣Complex cyanotic congenital heart disease
‣Repaired congenital defects corrected with prosthetic material or device
for six months
‣Repaired congenital defect with prosthetic material or device with partial
defect
‣Cardiac transplant patients with cardiac valvulopathy
Prophy ABX
Does total joint replacement require abx prophy?
Not routinely
Consider _____ weeks of antibiotic
after use of bone grafting
1 week
Do you want to do abx prophy before or after implant placement without bone grafting?
Only before
