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
what makes laser selection procedure dependent
- different laser wavelengths have different absorption coefficients with primary tissue components
what are the types of lasers
- diode lasers
- Nd: YAG
- Erbium
describe diode lasers and their use
- used in soft tissue treatment
- not effective for calculus removal
- low level laser has been recommended for pain reduction and enhancing would healing due to its anti inflammatory effects
describe the Nd: YAG laser and its use
- highly absorbed by the pigmented tissue
- effective in cutting and coagulating dental soft tissues
- used for nonsurgical sulcular debridement in periodontal disease control
describe the erbium laser and its use
- laser of choice for treatment of dental hard tissues
- high affinity for hydroxyapatite
- highest absorption of water in any dental laser wavelengths
- can be used for soft tissue ablation
what are the ideal properties for systemic antibiotics
- effective against all periodontal pathogens
- substantive and non toxic
- not in general use for other diseases
- no single antibiotic at concentrations achieved in GCF satisfies the above requirements
what are the adjunt therapies in phase 1 therapy
- tetracyclines: tetracycline and doxycycline
- penicillin: amoxicillin, augmentin
- azithromycin
- metronidazole
describe tetracyclines as an adjunct therapy and its characteristics
- high concentrations in GCF. (2-10 fold than serum)
- doxycycline has better compliance because it can be given qd or bid
- broad spectrum bacteriostatic
- antimicrobial effect: highly effective against A, actinomycetemcomitans but resistant strains are now common
- anti- collagenolytic effects: inhibit connective tissue destruction and promote repair
- photosensitivity: severe skin burns
describe penicillins as adjunct therapy
- a group of beta lactam antibiotics
- broad spectrum bactericidal
- affected by beta lactamases: can be protected by clavulanic acid
- up to 10% of humans are allergic to penicillins
- can be used in combo with metronidazole
what makes augmentin
amoxicillin + clavulanic acid
what can penicillins be substituted for
ciprofloxacin, azithromycin, clindamycin
what are the charactersistics of azithromycin
- bacteriostatic for most pathogens
- effective against most anaerobes, gram positive and negative bacteria
- good tissue concentration
- better compliance because it is given qd
- can be used in combination with metronidazole
describe the characteristics of metronidazole
- attain effective antibacterial concentration in gingival tissue and GCF
- particularly effective against anaerobic bacteria and spirochetes
- bactericidal
- adverse reaction (nausea, vomiting, cramping) when taken with alcohol
what should you not combine metronidazole with
warfarin, lithium, phenytoin, cyclosporin
what is the antibiotic regiment in phase 1 therapy
- 7-10 days
- metronidazole: 500mg tid for 8 days
- clindamycin: 300 mg tid for 8 days
- doxycyclnine or minocycline: 100-200mg qd for 21 days
- ciprofloxacin: 500 mg bid for 8 days
- azithromycin: 500 mg qd for 4-7 days
- metronidazole + amoxicillin: 250 mg tid for 8 days
- metronidazole + ciprofloxacin: 500mg bid for 8 days
describe the metronidazole + amoxicillin combo therapy in phase 1 therapy
- van winkelhoff cocktail: 375mg amox + 250 mg metro TID 7 days
- 500 mg Amox + 500mg Metro TID
- 250 mg Amox + 250mg Metro TID or QID
- 7 or 14 days of administration
what is the antibiotic regiment in acute periodontal abscess
- amoxicillin loading dose of 1g followed by 500mg TID for 3 days
- if allergy to Beta lactam drugs: azithromycin loading dose of 1g on day 1 followed by 500mg/QD for days 2 and 3
- OR clindamycin loading dose of 600mg on day 1 followed by 300 mg QID for 3 days
what is the goal of host modulation
to reduce tissue destruction by modifying the host response
what is the process of health to disease in host modualtion
- pioneer bacteria colonization
- biofilm formation
- congregation of early colonizers
- acquisition of bridging bacteria
- accumulation of keystone pathogens
- dysbiosis + host immune reposnse
what happens in host modulatoin
- reduce excessive amounts or activity of lytic enzymes/cytokines/inflammatory mediators
- increase anti inflammatory mediators or activity
- modulate osteoblast and osteoclast activity
- no impact on physiologic cell function; contribute to sustained control of harmful drugs
- promote connective tissue repair or regeneration and produce clinically significant results
what do NSAIDs do and their SE
- target prostaglandins and inflammation
- selective COX-1 and COX-2 inhibitors
- indomethacin, flurbiprofen, and naproxen long term daily use up to 3 years can lead to slower disease progression
- serious side effects such as GI irritation, liver and renal damage/dysfunction
- not used as adjuncts in routine periodontal therapy
what do bisphosphonates do
- disrupt osteoclast activity
- can improve alveolar bone density but the role in disease progression in humans is unclear
- serious side effects with IV agents ( ONJ)
- no approved application in perio therapy
what do tetracyclines do
- inhibit CT breakdown
- mediated by extracellular mechanism
- mediated by cellular regulation
- mediated by pro anabolic effects
what extracellular mechanisms mediate tetracycline
- direct inhibition of active MMPs
- inhibition of oxidative activation of Pro-MMPs
- inhibition of MMPs indirectly decreases serine proteinase activity
how cellular regulations are mediating tetracyclines
- TCs decreases cytokines, iNOS, PLA, prostaglandin synthase
- effects on protein kinases
what pro anabolic effects mediate tetracyclines
- TCs increases collagen production
- TCs increase osteoblast activity and bone formation
what is subantimicrobial dose doxycycline
among tetracyclines, doxycycline has the best anti colalgenolytic activity and better GI absorption
- the only FDA approved host modifier as an adjunct to SRP
what is the subantimicrobial dose doxycycline administration
- 20mg doxycycline twice daily or 40 mg once daily for 6-9 months
- adjunct to thorough and high standard SRP
- SDD doesnt result in antibacterial effects/development of resistant strains/multi antibiotic resistance
- may reduce efficacy of contraceptives
what is SDD contraindicated in and why
pregnancy or children for the risk of permanent teeth discoloration
what is the SDD form and how is it administered
- periostat is a host modulating agent
- inhibits host collagen degrading enzymes
- FDA approved host modifier as an adjunct to SRP
- do not use as stand alone therapy
what is the clinical significance of SDD
0.2-0.4mm difference in attachment gain
antibiotic prophylaxis is used in what conditions
heart conditions and prosthetic joints
antibiotic prophylaxis apply only to dental procedures requiring:
manipulation of the gingival tissue or the periapical region of the teeth or perforationof the oral mucosa
what patients are at highest risk of IE
- prosthetic cardiac valves/material
- congenital heart disease
- previous, relapse or recurrent IE
- cardiac transplant recipients who develope cardiac valvulopathy
what is more important to prevent IE than AB prophylaxis
maintaining good oral health and regular dental care
for patients with prosthetic joint implants prophylacti AB are ______ recommended prior to dental procedures to prevent infection
NOT
patients with history of complications associated with their joint replacement undergoing dental procedure you need to:
consult with patient and orthopedic surgeon
what is the prophylactic regiment
- single dose 30-60 minutes before procedure
- amoxicillin of 2g
- azithromycin of 500mg
- clarithromycin of 500mg
why is clindamycin no longer recommended for dental procedure antibiotic prophylaxis
more frequent and serious adverse effects associated with clindamycin compared to others, including C. difficile infections
consider_______ of antibiotic use following bone and soft tissue grafting
1 week
is antibiotic prophylaxis indicated prior to implant placement
yes
what is the management of SLE
- rheumatologists: organ specific approach
- long term prednisone
- immunomodulating agents
what are the oral manifestations of SLE
- SLE like lichenoid lesions
- ulcerations/erosions
- hard palatal mucosal ulcer
- white radiating striae from a central ulcer
what are the dental considerations with SLE
- leukopenia
- thrombocytopenia (25% of patients)
- nonbacterial verrucous valvular libman sacks endocarditis
- renal disease
- neuropsychiatric disease
what is the pathogenesis of RA
- unknown etiology
- environmental, hormonal, infectious factors, in a genetically predisposed individual
- external trigger elicits an autoimmune reaction
- hypertrophy of the synovial lining of the joint and endothelial cell activation
- uncontrolled inflammation and destruction of cartilage and bone
what are the complications of RA
joints and extra articular involvement
what is the epidemiology of RA
1.3 million US adults
- women 3 times more affected than men
- sex difference diminish in older age groups, suggesting a hormonal component
what is the dx of RA
- 6/10 score based on a 4 prong algorithm
-1. joint involvement
-2. serology test results (RA factor, ACPA)
-3. acute phase reactant test results
-4. pt self reporting of signs/symptoms duration
what are the autoantibodies associated with RA
- ANA: 30-60%
- antinative DNA: 0-5%
- RF: 72-85%
- anti-Sm: 0%
- anti-Ro: 0-5%
- Anti-La: 0-2%
what is the defining characteristis of RA when compared to osteoarthritis
- multiple symmetric joint involvement
- significant joint inflammation
- morning joint stiffness lasting longer than 1 hour
- symmetric, spindle-shaped swelling of PIP joints and volar subluxation of MCP joints and Bouchard’s nodes of PIP joints
- systemic manifestations (fatigue, weakness, malaise)
what are the defining characteristics of osteoarthritis when comparing against RA
- usually one or two joints involved
- joint pain usually without inflammation
- morning joint stiffness lasting less than 15 minutes
- Heberden nodes of DIP joints
- no systemic involvement
what is the management of RA
- nonpharmacological: physical, occuptional therapies, orthotic devices, surgery
- pharmacological: NSAIDs, disease modifying antirheumatic drugs, immunosuppressants, biological response modifiers, corticosteroids
what are the oral manifestations of RA
- TMJ dysfunction
- medication induced ulcerations
- salivary hypofunctionw
what are the dental considerations for RA
- ADA guidelines on prophylactic antibiotics for pts with prosthetic joints undergoing dental procedures
what is the suggested AB regimen for patients not allergic to penicillin
cephalexin, cefradine, or amoxicillin
what is the suggested AB regimen to patients not allergic to penicillin and unable to take oral meds
cefazolin or ampicillin IV or IM
what is the suggested AB regimen for patients allergic to penicillin
clindamycin
what is the suggested AB regiment for patients allergic to penicillin
clindamycin
what is the suggested AB regimen for patients allergic to penicillin and unable to take oral meds
clindamycin IV
what is the pathogenesis of progressive systemic sclerosis
- unknown etiology
- endothelial cell injury
- fibroblast activation
- vascular dysfunction
what are the complications of progressive systemic sclerosis
skint thickening/induration
- tissue fibrosis and chronic inflammation
- infilatration of heart, lungs, and kidneys
- prominent fibroproliferative vascular disease
what is the epidemiology of progressive systemic sclerosis
- peak onset 30-50years
- 4-9 times higher in women than in men
what is the diagnosis of localized scleroderma
- skin on the hands and face
- slow disease course
- indolent and rarely spreads more widely or results in serious complications
what is the diagnosis of progressive systemic sclerosis
- affects large areas of skin and heart, lungs or kidneys
- 2 main types of systemic scleroderma: limited disease or CREST syndrome, calcinosis, Raynaud’s syndrome, esophageal dysmotility, sclerodactyly, telangiectasia
- diffuse disease
what are the autoantibodies associated with diffuse scleroderma
- ANA: 80-95%
- antinative DNA: 0%
- RF: 25-33%
- Anti-Sm: 0%
- Anti-Ro: 0%
- Anti- La: 0%
what is the management for progressive systemic sclerosis
- long term prednisone
- immunomodulating agents
what are the oral manifestations and dental considerations for progressive systemic sclerosis
- severe microstomia, trismus, submucosal fibrosis
- elongation exercises to improve trismus
