Current use of Antibiotics and Antimicrobials Flashcards
what is the philosophy of treatment
- periodontitis is caused by bacteria
- a chronic disease
- recurs or re-infects
- arrest the disease
- alter the microflora to prevent reinfection
- maintain the disease in an arrested state
what is the effective antimicrobial
- target microflora
- does no harm
- has a sufficient duration
- reaches the site
- has an adequate concentration
cumulative oral dosage can have the problem of:
side effects such as GI problems or tolerance
small dose of local delivery antimicrobial leads to:
high concentration at crevicular level
what is the dosage of tetracycline delivered systemically and locally
- systemically: 2 micrograms in peripheral blood level;16 micrograms in GCF
- delivered locally: 1600 micrograms in GCF
an antiobiotic strength ______ than the systemic dose may be required to be effective against the bacteria residing in plaque biofilms
500 times greater
how do antibiotic agents gain access to the periodontal pathogens and inhibit biofilm formation
disrupt the biofilm physically
never use antimicrobial agents in the absence of:
mechanical debridement
what is the most effective rinsing agent for plaque inhibition and prevention of gingivitis
chlorhexidine gluconate
describe chlorhexidine gluconate
- 0.12% chlorhexidine gluconate
- no systemic toxicity, hypersensitivity is rare
- active against most bacteria and fungi
- no microbial resistance was reported
- cannot predictably reach the subgingival area
what are the SE of chlorhexidine
taste alteration, tooth discoloration, increased supragingival calculus formation
- extrinsic brown discoloration on the teeth from an individual rinsing twice a day for 3 weeks with 0.12% formulation
what is the mechanism of chlorhexidine
chlorhexidine is a positively charged molecule that binds to the negatively charged sites on the cell wall; it destabilizes the cell wall and interferes with osmosis
- high substantivity
- adhere to soft and hard tissues and then be released over time
- slow release over 12 hours
lower concentrations of chlorhexidine leads to:
increased permeability and leakage
higher concentrations of chlorhexidine lead to:
precipitation of cytoplasmic contents including microbial cell death
what is the application of chlorhexiine
- as an adjunct to regular OH during phase I therapy in high risk individuals
- mentally or physically challenged patients with low manual dexterity
- jaw fixation, BRONJ
- 1st-2nd week post surgery
describe essential oils as a mouth rinse
- mouth rinse with eucalyptol, menthol, methyl salicylate, thymol
- antiplaque effects and a significant reduction in gingivitis index
- side effects: burning sensation and tooth staining
what are the side effects of mouth rinses
- most anti plaque rinses contain alochol as a vehicle to deliver antiseptic ingredients
- critical assessment of the literature does not support an associated between alcohol rinses and cancer
- not recommended for recovering alcoholics and in patients taking metronidazole or disulfiram
what are the mechanisms possible for mouth rinses
- cell wall disruption
- inhibition of bacterial enzymes
- extraction of endotoxings derived from LPS of gram negative bacteria
- anti-inflammatory action based on antioxidant activity
beneficial effects were seen with H2O2 levels of:
greater than 1%
prolonged use of H2O2:
decreased plaque and gingivitis indices
therapeutic delivery of H2O2 to prevent periodontal disease required:
mechanical access to subgingival pockets
what are the SE of hydrogen peroxide
- 3% HwOw or less used daily showed occasional irritant effects
- in a small number of subjects with preexisting ulceration
- when combined with high levels of salt solutions
- 30% H2O2 was referred to as a co-carcinogen
- ADA and FDA have concerns with long term use
what are the forms of direct delivery
subgingival irrigations/local antimicrobial delivery/laser therapy
describe subgingival irritation
- significantly reduced certain bacteria when used as monotherapy but not eliminated
- microbiota rebound to baseline within1-8 weeks after short term subgingival irrigation
- tissue invasive organisms dont respond well
- after 6 months with irrigation every 2 weeks with 3% hydrogen peroxide, limited success was achieved in reducing high concentrations of actinobacillus actinomycetemcomitans
what are the properties of subgingival irritation
- reaches the site with a sufficient concentration
- achieved 90% penetration in pockets of less than 6mm when the tip was placed 1mm apical to the margin
- 70-80% penetration in deeper pockets when cannula was placed 3mm apical to the margin
- lack of substantivity
- blood and protein can deactivate the drug
- the medicament may not be retained long enough to have an efficacious effect
- 50% of a fluorescein label hydroxyporyl cellulose gel injected subgingivally was wahsed out of pockets in 12.5 minutes
- the gingival crevicular fluid is replaced in a 5mm pocket 40 times over an hour period
- the half life of an antimicrobial irrigation concentration is 1 minute
describe the appilcation of subgingival irritation
- 0.12% chlorhexidine
- single use to reduce the bacterial load; adjunctive use to gain the antiseptic effect
- a syringe and a jet irrigator with a cannula were equally effective. low irrigation forces were effective
- betadine can be used diluted as an irrigant
- dont use with hx of iodine sensitivity
- use with caution in pregnancy and lactation to prevent inducing transient hypothyroidism in newborns
describe local antimicrobial delivery
the medicament placed in a periodontal pocket with a delivery system and released in a controlled manner allowing minimum inhibitory concentration for 7 days
what are the ideal properties of LAD
- effective against periodontal pathogens: kill the pathogens, reach the site wall
- low risk of bacterial resistance
- low systemic absorption: good concentration and substantivity
- biodegradable
- easy to use
- enhances scaling and root planing
what are the indications for LAD
- when local sites with inflammation have not responded to periodontal or maintenance therapy
- residual isolated pockets greater than 5mm not responding favorable to initial SRP with BOP at re evaluation
- residual pockets after periodontal surgery
- recurrent isolated pockets greater than 5mm with BOP at maintenance
- always as adjunct therapy never use alone**
what are the common products for LAD
- PerioChip
- Atridox
- Arestin
- Acisite
what is the delivery platform and active agent for PerioChip
- degradable film
- chlorhexidine gluconate (2.5mg)
what is the delivery platform and active agent for Atridox
- biodegradable gel ( two syringe mixing)
- doxycyline hyclate (50mg)
what is the delivery platform and active agent for arestin
- microspheres (powder by syringe)
- minocycline hydrochloride (1mg)
what is the delivery platform and active agent for acisite
- non- biodegradable fibers
- tetracyline hydrochloride (12.7mg)
describe the use of PerioChip
- bioresorbable polymer with 2.5mg chlorhexidine
- inserted into the pocket greater than 5mm
- release takes 7 days
- dissolves within 7-10 days, does not require removal
- significant improvement in CAL when used with SRP
describe the use of doxycycline hyclate gel
- atridox: 10% doxycyline hyclate
- delivered subgingivally by cannula to flow to the base of the pocket and adapt to root morphology
- controlled release over 21 days
- significant improvement in CAL when used with SRP
- do not use in patients with hypersensitivity to doxycyline or drugs in the tetracycline class
describe the use of minocycline/microsphere
- arestin: 1mg minocycline hydrochloride in bioabsorbable micropsheres
- bacteriostatic by inhibiting protein synthesis
- broad spectrum
- significantly reduced red- complex bacteria in smokers
- greater improvement in PD, CAL regardless of smoking status
describe tetracycline fiber use
- actisite: non resorbably, monolithic fiber contains 25% tetracycline HCL powder
- currently available
- slow release over 10 days
- packed into the pocket and left in place for 7-12 days, need removal
- improve PD, BOP, CAL when combined use with SRP in 6 months but no difference after 5 years
describe LAD in peri implant diseases
- local drug delivery is not effective with implants
- may partially detoxify the implants but have no long lasting effects
- may be used as an adjunct to help with the inflammation
what does laser stand for in laser therapy
- Light
- Amplification by the
-Stimulated
-Emission of
-Radiation
what are the 3 basic structures of Laser Therapy
- an energy source
- an active lasing medium
- two or more mirrors that form an optical cavity or resonator
describe laser therapy
monochromatic light with a single wavelength
- the wavelength and other properties are determined primarily by the composition of an active medium
what are the 4 different interactions with a target tissue
- absorption
- transmission
- scattering
- reflection
what do absorbing chromophores act on
- intraoral soft tissue: melanin, hemoglobin
- dental hard tissues: water and hydroxyapatite
describe absorption in laser therapy
- light energy is converted into heat and photochemical effects occur depending on the water content of the tissues
- between 60-100 celsius proteins begin to denature without vaporization of the underlying tissue
- when reaching 100 celsius, vaporization of the water within the tissue occurs- ablation
- at temperatures over 200 celsius the tissue is dehydrated and then burned resulting in carbonization